A method of digitally printing a solder mask. The method includes providing a solder mask ink composition including: 1) a resin and 2) a solvent in an amount of at least 20% by weight relative to the total weight of the solder mask ink composition. The composition has a viscosity that is less than 1000 cps at a shear rate of 10 s.sup.1 and a temperature of 25 C. An aerosol stream is generated from the solder mask ink composition with a pneumatic atomizer using an atomization gas. The aerosol stream is directed through a nozzle and focused using a sheath gas onto a substrate while changing the position of the nozzle with respect to the substrate to selectively deposit a solder mask pattern. The solder mask pattern is cured.

An adaptive interposer is provided to be operably disposable between first and second solder materials of first and second electronic devices, respectively. The adaptive interposer includes a plate element formed to define cavities and third solder material disposable in the cavities to be electrically communicative with the first and second solder materials. The third solder material is more compliant and has a higher melting temperature than at least the second solder materials.

An electronic device is provided. The electronic device includes a housing forming an exterior of at least part of the electronic device, a battery disposed to an inner space of the electronic device formed by the housing, and a printed board assembly (PBA) disposed between the battery and a side member of the housing in the inner space, the PBA including a first printed circuit board (PCB), a second PCB, and an interposer PCB disposed between the first PCB and the second PCB to connect the first PCB and the second PCB, wherein the interposer PCB includes an insulating layer which includes a first face and a second face opposite to the first face, a first via group which penetrates the insulating layer to connect the first face and the second face, and includes a plurality of first vias formed spaced apart from each other, the plurality of first vias included in the first via group being used as a first transmission path through which a first signal passes, a first conductive pad which is disposed on the first face to cover first holes of the plurality of first vias, formed on the first face, and is electrically coupled to the plurality of first vias, and a first solder layer which is disposed on the first conductive pad, wherein the first conductive pad extends by a first width in a first direction along the first face of the insulating layer, and wherein the first solder layer extends by a second width smaller than the first width in the first direction.

A method of digitally printing a solder mask. The method includes providing a solder mask ink composition including: 1) a resin and 2) a solvent in an amount of at least 20% by weight relative to the total weight of the solder mask ink composition. The composition has a viscosity that is less than 1000 cps at a shear rate of 10 s.sup.1 and a temperature of 25 C. An aerosol stream is generated from the solder mask ink composition with a pneumatic atomizer using an atomization gas. The aerosol stream is directed through a nozzle and focused using a sheath gas onto a substrate while changing the position of the nozzle with respect to the substrate to selectively deposit a solder mask pattern. The solder mask pattern is cured.

A wiring board includes plural terminals, an insulating layer, and recess portions. Each terminal includes a roughened upper surface and a roughened side surface. The insulating layer is formed between the terminals. The upper surfaces of the terminals are exposed. An upper surface of the insulating layer is a concave curved surface. The recess portions are formed in the insulating layer around the terminals so as to partially expose the side surfaces of the terminals.

A method of digitally printing a solder mask. The method includes providing a solder mask ink composition including: 1) a resin and 2) a solvent in an amount of at least 20% by weight relative to the total weight of the solder mask ink composition. The composition has a viscosity that is less than 1000 cps at a shear rate of 10 s.sup.1 and a temperature of 25 C. An aerosol stream is generated from the solder mask ink composition with a pneumatic atomizer using an atomization gas. The aerosol stream is directed through a nozzle and focused using a sheath gas onto a substrate while changing the position of the nozzle with respect to the substrate to selectively deposit a solder mask pattern. The solder mask pattern is cured.

A wiring board includes a plurality of insulating layers each being made of flexible insulating resin, and a conductor layer that is laminated on the plurality of insulating layers and that has a conductor pattern. The conductor layer includes a conductor pattern that has a certain shape in which a plurality of unit patterns are connected in plan view. The unit pattern includes a U-shaped pattern, an inverted U-shaped pattern that is arranged such that an opening side is located away from an opening side of the U-shaped pattern, and a straight line pattern that connects center portions of the U-shaped pattern and the inverted U-shaped pattern.

A mounting structure of an electronic component includes a multilayer ceramic capacitor including lands on a board and spaced apart from each other, solder on the lands, and a component main body including external electrodes on both end portions of the component main body in a length direction, each of the pair of external electrodes being connected to a corresponding one of the pair of lands via the solder. When a separation direction of the lands is an X direction and a direction orthogonal or substantially orthogonal to the X direction is a Y direction, when a width dimension of the land along the Y direction is c, a dimension of each of the external electrodes in the X direction is e, and a gap between the land and the external electrode is Gap, 3.4<(ce)/Gap<258.8 is satisfied.

A disclosed circuit board includes: a first insulating layer that has a first surface and a second surface opposing each other; a first wire layer that is buried within the first insulating layer; and a bump that includes a base portion disposed laterally to the first wire layer to be buried within the first insulating layer and a protrusion portion integrally extending and protruding from the base portion and having a width at an upper end thereof less than a width of the protrusion portion at a height of the first surface.

A printed circuit board includes a first insulating layer, a metal pad including a first metal portion disposed on the first insulating layer, and a second metal portion disposed on the first metal portion and integrated with the first metal portion without a boundary therebetween, the second metal portion having a width narrower than a width of the first metal portion on a cross section, a second insulating layer disposed on the first insulating layer and covering at least a portion of a side surface of the first metal portion, and a surface metal layer disposed on the metal pad and covering at least a portion of each of an upper surface and a side surface of the second metal portion.