A wiring substrate includes an insulating layer, a conductor layer formed on a surface of the insulating layer such that the conductor layer includes a conductor pad, and a solder resist layer formed on the surface of the insulating layer such that the solder resist layer is covering the conductor layer and having an opening exposing the conductor pad. The conductor pad of the conductor layer has a substantially rectangular planar shape such that the conductor pads has a main surface, a pair of long sides, a pair of short sides and four corner portions, and the solder resist layer is formed such that the opening is exposing side surfaces at the long sides and 50% or more of the main surface and that the solder resist layer is covering side surfaces at the short sides.

A method for manufacturing a circuit board embeds a portion of an outer circuit layer in an outer dielectric layer which increases contact area between the outer circuit layer and the outer dielectric layer, improving adhesion between the outer circuit layer and the outer dielectric layer, and reducing a thickness of the outer circuit substrate, thereby reducing the overall thickness of the finished circuit board.

Disclosed is a printed circuit board according to an embodiment. The printed circuit board comprises: a base board; a metal layer, including a pad and a metal line formed in the base board; a solder resist layer that is formed on the base board on which the metal layer is formed and has an opening through which the surface of the metal line is exposed; and an underfill that is formed between the solder resist layer and a semiconductor chip electrically connected to the pad and includes a blocking area formed in the opening.

A printed circuit board includes: an insulating layer; a plurality of pads disposed on the insulating layer; and a plurality of insulating walls disposed on the insulating layer, and at least partially covering side surfaces of the plurality of pads, respectively, while being free from surfaces of the plurality of pads, respectively. The plurality of insulating walls are disposed to be spaced apart from each other on the insulating layer.

A method for curing solder paste on a thermally fragile substrate is disclosed. An optically reflective layer and an optically absorptive layer are printed on a thermally fragile substrate. Multiple conductive traces are selectively deposited on the optically reflective layer and on the optically absorptive layer. Solder paste is then applied on selective locations that are corresponding to locations of the optically absorptive layer. After a component has been placed on the solder paste, the substrate is irradiated from one side with uniform pulsed light. The optically absorptive layer absorbs the pulsed light and becomes heated, and the heat is subsequently transferred to the solder paste and the component via thermal conduction in order to heat and melt the solder paste.

A printed circuit board has an in-pad via. In a first step, a component is mounted on a first surface of a printed circuit board. A screen to be used in a second step has openings at positions corresponding to those of a plurality of pads on a second surface and has a recess positioned to overlap an in-pad via. Solder cream is applied from above the screen, and the screen is removed. Then, a component is mounted on the second surface.

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.

A circuit board includes a composite structure layer, at least one conductive structure, a thermally conductive substrate, and a thermal interface material layer. The composite structure layer has a cavity and includes a first structure layer, a second structure layer, and a connecting structure layer. The first structure layer includes at least one first conductive member, and the second structure layer includes at least one second conductive member. The cavity penetrates the first structure layer and the connecting structure layer to expose the second conductive member. The conductive structure at least penetrates the connecting structure layer and is electrically connected to the first conductive member and the second conductive member. The thermal interface material layer is disposed between the composite structure layer and the thermally conductive substrate, and the second structure layer is connected to the thermally conductive substrate through the thermal interface material layer.

An electronic device package is disclosed. The electronic device package includes a board on which an electronic device is mounted, a molded portion formed to cover the electronic device on the board, and a conductive layer disposed on a surface of the molded portion and extended in a trench formed on the board.

A system for effectively curing dry film ink throughout its thickness on circuit boards being made applies an exposure system, a circuit board, and a method for making the circuit board. The exposure system includes a plurality of mixed light sources with different wavelengths within a range of 365 nm to 440 nm, the mixed light sources can output at least three different wavelengths of light each of substantially a single wavelength and a fourth source of light able to output light of a spectrum of wavelengths, the ranges of light being between 365 nm and 440 nm.