A connection method for a chip and a circuit board includes: placing the circuit board on the chip, the circuit board having a first surface in contact with the chip having a plurality of contacts, and the circuit board having a plurality of through holes aligned with the plurality of contacts respectively; placing a mask on a second surface of the circuit board, the mask having a plurality of openings aligned with the plurality of through holes respectively; covering a surface of the mask with a conductive adhesive to fill the plurality of through holes with the conductive adhesive; and keeping portions of the conductive adhesive that are respectively in the plurality of through holes to be spaced apart from each other. The portions of the conductive adhesive that fill the plurality of through holes remain to provide an electrical connection between the circuit board and the chip.

One or more masks may be used to control the application of protective (e.g., moisture-resistant, etc.) coatings to one or more portions of various components of an electronic device during assembly of the electronic device. A method for applying a protective coating to an electronic device includes assembling two or more components of the electronic device with one another. A mask may then be applied to the resulting electronic assembly. The mask may shield selected portions of the electronic assembly, while other portions of the electronic assembly, i.e., those to which a protective coating is to be applied, may remain exposed through the mask. With the mask in place, application of a protective coating to portions of the electronic assembly exposed through the mask may commence. After application of the protective coating, the mask may be removed from the electronic assembly. Embodiments of masked electronic assemblies are also disclosed.

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 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 mask device includes a mesh mask and a metal mask disposed under the mesh mask. The mesh mask includes a mesh pattern and a plurality of first blocking portions disposed in the mesh pattern to block portions of the mesh pattern, the metal mask includes a plurality of second blocking portions overlapping the first blocking portions in a plan view, and the metal mask is provided with an accommodation opening defined through in the metal mask, and not overlapping the first blocking portions in a plan view.

A circuit board includes a circuit board plate, a conductive ring, a solder mask and at least one insulating pad. The circuit board plate includes a surface and a conductive through hole passing through the surface and the circuit board plate, wherein the conductive through hole have a conductive layer disposed on a wall thereof. The conductive ring on the surface surrounds an opening of the conductive through hole on the surface and electrically connects to the conductive layer. The solder mask is disposed on the surface. The conductive ring is exposed outside of the solder mask. The insulating pad has a thickness. The first surface of the insulating pad is adapted to contact the solder mask or the surface and sited at periphery of the conductive ring. The second surface of the insulating pad is adapted for spacing a distance between a solder coating tool and the solder mask.

In an example, a process for bonding a dry film solder mask (DFSM) material to a printed circuit board (PCB) laminate material is disclosed. The process includes applying a DFSM material that includes a dienophile functional group to a PCB laminate material that includes a diene functional group. The process further includes bonding the DFSM material to the PCB laminate material via a chemical reaction of the dienophile functional group with the diene functional group.

An apparatus and method for manufacturing a power module is provided. The power module includes: a circuit board having a metal pattern formed thereon; a terminal coupled to the circuit board and electrically connected to at least a portion of the metal pattern; a power device chip bonded to the circuit board and electrically connected to at least a portion of the metal pattern and the terminal; and a molding part covering the power device chip and the circuit board. The circuit board includes: a base part comprising an insulating material; a pattern layer disposed on at least one of an upper surface and a lower surface of the base part and providing the metal pattern; and a thin film resistor having a predetermined circuit pattern connecting the metal patterns disposed on the base part to each other.