A method of controlling alloy composition of deposited gold-tin alloy during electroplating of a large panel includes masking at least one planar surface of the panel with conductive material applied in a predetermined pattern. The masked panel is located at least partially within an electroplating solution including a gold-tin alloy in solution at a predetermined gold:tin ratio. Electrical current applied to the masked panel is conducted across the planar surface via the conductive material to induce a predetermined electrical current distribution across the planar surface and thereby pull gold ions and tin ions from the electroplating solution. The pulled ions are deposited upon a supermajority of an unmasked area of the masked panel. The predetermined pattern is selected to achieve deposition of the gold-tin alloy with substantially uniform alloy composition, directly corresponding to the predetermined gold:tin ratio, across the supermajority of the unmasked area of the masked panel.

A circuit board structure includes an inner circuit structure and a first build-up circuit structure. The inner circuit structure includes a core layer having an upper surface and a lower surface, a first patterned circuit layer disposed on the upper surface, a second patterned circuit layer disposed on the lower surface and a conductive through hole connecting the first and the second patterned circuit layers. The first build-up circuit structure at least has a cavity and an inner dielectric layer. The inner dielectric layer has an opening communicating the cavity and a pad of the first patterned circuit layer is located in the opening. A hole diameter of the opening is smaller than a hole diameter of cavity. An inner surface of the inner dielectric layer exposed by the cavity and a top surface of the pad are coplanar or have a height difference.

A circuit board structure includes an inner circuit structure and a first build-up circuit structure. The inner circuit structure includes a core layer having an upper surface and a lower surface, a first patterned circuit layer disposed on the upper surface, a second patterned circuit layer disposed on the lower surface and a conductive through hole connecting the first and the second patterned circuit layers. The first build-up circuit structure at least has a cavity and an inner dielectric layer. The inner dielectric layer has an opening connecting the cavity and exposing a portion of the first patterned circuit layer. A hole diameter of the opening is smaller than a hole diameter of cavity. A height difference is between an inner surface of the inner dielectric layer exposed by the cavity and a top surface of the first patterned circuit layer exposed by the opening.

A method of manufacture of a circuit board without annular through-hole rings and thus allowing a higher component density includes a base layer, a first wire pattern layer, and a second wire pattern layer on both sides of the base layer. A portion of the base layer not covered by the first wire pattern layer defines at least one first hole. The circuit board further includes a wire layer. The wire layer includes at least a first portion and a second portion connecting to the first portion. The first portion is filled in the first hole. The second portion is formed on the first portion extending away from the base layer. A diameter of the second portion is less than an aperture diameter of the first hole. The wire layer is electrically conductive between the first wire pattern layer and the second wire pattern layer through the first portion.

A printed circuit board is provided. The printed circuit board comprises a base substrate comprising a chip mounting region on an upper surface thereof, a plurality of connection pad structures in the chip mounting region, and an extension pattern on the base substrate, spaced from each of two adjacent connection pad structures from among the plurality of connection pad structures, and extending along the two adjacent connection pad structures. Upper surfaces of the plurality of connection pad structures are positioned at a higher level than an upper surface of the extension pattern.

A method for printing on a substrate, the method may include determining actual locations of substrate holes; printing a first ink on an object at locations that correspond to the actual locations of the substrate holes and curing the first ink to provide a holes mask; and wherein after the substrate is positioned on the object so that holes mask seals bottoms of the substrate holes then printing the second ink on the substrate thereby forming a predefined pattern on the substrate.

A fabrication process of a stepped circuit board comprises A) cutting a circuit board substrate, printing patterns on an inner layer of the circuit board substrate, stepped groove milling of the inner layer, washer milling a washer between the inner layer and an outer layer, brownification and lamination processing on the inner layer, and then drilling holes on an outer layer of the circuit board substrate; B) electroplating the entire circuit board substrate by depositing copper on the outer layer of the circuit board substrate with drilled holes; C) performing pattern transfer by means of through-hole plating of the drilled holes on the circuit board substrate processed by the copper depositing and the electroplating; D) after pattern transferring, grinding a shape of a connecting piece (SET) on the circuit board substrate after the electroplating; E) plugging the drilled holes to form plug holes and printing a solder mask and texts in a silk-screen manner after forming the plug holes; F) depositing nickel immersion gold on the entire circuit board substrate, then printing characters in a silk-screen manner, thereby forming the stepped circuit board; and G) testing and inspecting an electric performance and appearance of the stepped circuit board to fabricate a finished product of the stepped circuit board.

A circuit board structure includes an inner circuit structure and a first build-up circuit structure. The inner circuit structure includes a core layer having an upper surface and a lower surface, a first patterned circuit layer disposed on the upper surface, a second patterned circuit layer disposed on the lower surface and a conductive through hole connecting the first and the second patterned circuit layers. The first build-up circuit structure at least has a cavity and an inner dielectric layer. The inner dielectric layer has an opening communicating the cavity and a pad of the first patterned circuit layer is located in the opening. A hole diameter of the opening is smaller than a hole diameter of cavity. An inner surface of the inner dielectric layer exposed by the cavity and a top surface of the pad are coplanar or have a height difference.

A circuit board structure includes an inner circuit structure and a first build-up circuit structure. The inner circuit structure includes a core layer having an upper surface and a lower surface, a first patterned circuit layer disposed on the upper surface, a second patterned circuit layer disposed on the lower surface and a conductive through hole connecting the first and the second patterned circuit layers. The first build-up circuit structure at least has a cavity and an inner dielectric layer. The inner dielectric layer has an opening connecting the cavity and exposing a portion of the first patterned circuit layer. A hole diameter of the opening is smaller than a hole diameter of cavity. A height difference is between an inner surface of the inner dielectric layer exposed by the cavity and a top surface of the first patterned circuit layer exposed by the opening.

A method of making a printed circuit board pallet is provided. The method of making the pallet illustratively includes the steps of: providing a base in a form of a polymer sheet stock; applying a fluid onto the base at selective locations where the pallet will be built-up to a three-dimensional form; depositing a polymer powder onto the base at the selective locations applied with the fluid; removing any excess amounts of the polymer powder not adhered to the fluid; and heating the pallet to fuse the polymer powder together and to the base.