A copolymer is formed by reacting (A) aromatic monomer, an oligomer thereof, or a polymer thereof, with (B) aliphatic monomer, an oligomer thereof, or a polymer thereof. The aromatic monomer has a chemical structure of

##STR00001##

in which each of R.sup.1 is independently H or CH.sub.3, and n=1-4. R.sup.2 is a single bond, —O—,

##STR00002##

Each of R.sup.3 is independently

##STR00003##

A printed circuit board comprises N power switching cells operating in parallel and respectively comprising a transistor leg, at least one decoupling capacitor and a gate driver circuit. Each transistor leg comprises respective first and second transistors in series, a drain of the first transistor being connected to a positive DC line, a source of the second transistor being connected to a negative DC line, a source of the first transistor being connected to a drain of the second through a connection middle-point connected to an output terminal. Each gate driver circuit controls respective switching ON and OFF of the corresponding first and second transistors. The N transistor legs of the corresponding N power switching cells are positioned to substantially form a convex polygon having N edges of substantially the same length, each one of the N transistor legs being positioned along one of the edges of the convex polygon.

An optical engine module including a circuit board, a light valve module, a thermal conductive member, and a supporting member is provided. The circuit board having a first surface, a second surface opposite to the first surface, a first opening hole and at least one second opening hole. The light valve module is disposed on the first surface and electrically connected to the circuit board. The thermal conductive member is disposed on the second surface of the circuit board and is connected to a back surface of the light valve module through the first opening hole of the circuit board. A supporting member is disposed on one side of the first surface of the circuit board. The supporting member is partially in contact with the light valve module, and is connected to the thermal conductive member through the at least one second opening hole of the circuit board.

A component carrier includes a stack having at least one horizontal electrically conductive layer structure, at least one electrically insulating layer structure, a semiconductor component embedded in the stack, and at least one vertical via being laterally offset from the semiconductor component. The at least one horizontal electrically conductive layer structure electrically connects the vertical via to a bottom main surface of the semiconductor component. The component carrier is configured for a current flow from the vertical via to the horizontal electrically conductive layer structure, from the horizontal electrically conductive layer structure to the bottom main surface of the semiconductor component, from the bottom main surface of the semiconductor component to an upper main surface of the semiconductor component, and from the upper surface of the semiconductor component to the outside of the component carrier.

An electronic device includes a substrate, a first plate having a first internal surface facing a first surface of the substrate, and at least one first through-hole and at least one second through-hole, first and second semiconductor packages spaced apart from each other between the first surface and the first internal surface, a first thermal interface material layer contacting an upper surface of the first semiconductor package and the first internal surface, and filling at least a portion of the at least one first through-hole, and a second thermal interface material layer contacting an upper surface of the second semiconductor package and the first internal surface, and filling at least a portion of the at least one second through-hole. At least one of side surfaces of the first and second thermal interface material layers is exposed to an empty space between the first internal surface and the first surface.

A printed wiring board includes a core substrate including core material and having opening such that the opening penetrates through the core substrate, thermoelectric elements including P-type and N-type thermoelectric elements such that the thermoelectric elements are accommodated in the opening of the core substrate, a first build-up layer that mounts a heat-absorbing element thereon and includes a first resin insulating layer such that the first resin insulating layer is formed on first surface of the core substrate and covering the opening of the core substrate, and a second build-up layer that mounts a heat-generating element thereon and includes a second resin insulating layer such that the formed on the second resin insulating layer is foamed on second surface of the core substrate on the opposite side and covering the opening of the core substrate and has thickness that is greater than thickness of the first resin insulating layer.

The invention relates to a copper-ceramic composite, comprising a ceramic substrate, which contains aluminum oxide, a coating on the ceramic substrate made of copper or a copper alloy, wherein the aluminum oxide has an average grain form factor R.sub.a(Al.sub.2O.sub.3), determined as an arithmetic average value from the form factors of the grains of the aluminum oxide, the copper or the copper alloy has an average grain form factor R.sub.a(Cu), determined as an arithmetic average of the form factors of the grains of the copper or copper alloy, and the average grain form factors of the aluminum oxide and copper or copper alloy meet the following condition: 0.5≤R.sub.a(Al.sub.2O.sub.3)/R.sub.a(Cu)≤2.0.

Vias may be established in printed circuit boards or similar structures and filled with a monolithic metal body to promote heat transfer. Metal nanoparticle paste compositions may provide a ready avenue for filling the vias and consolidating the metal nanoparticles under mild conditions to form each monolithic metal body. The monolithic metal body within each via can be placed in thermal contact with one or more heat sinks to promote heat transfer.

A portable communication device is provided. A portable communication device includes a first nanofiber member having a first density, a second nanofiber member attached to the first nanofiber member and having a second density lower than the first density, a heat transfer member positioned on or above the second nanofiber member, and a conductive material coated on at least a portion of the first nanofiber member and the second nanofiber member. At least some of the conductive material may penetrate into the first nanofiber member or the second nanofiber member. Various other embodiments may be possible.

An electronic card includes a substrate, an electronic device bonded to the substrate via a solder bump, and configured to include a first ceiling, and a cover fixed to the substrate, provided over the electronic device, and configured to include a second ceiling that faces the first ceiling, wherein the first ceiling or the second ceiling is provided with an annular member extending in a facing direction of the first ceiling and the second ceiling, the annular member forming an annular shape along a circumferential direction of the first ceiling, wherein the first ceiling and the second ceiling form a gap between the first ceiling and the second ceiling filled with a filling material inside the annular member, and wherein the second ceiling includes a through hole at a position that overlaps the filling material when viewed in a plan view of the second ceiling.