A method for manufacturing a flex inlay is provided. The method includes providing a flexible printed circuit having opposed surfaces. The method includes attaching components to a surface of the flexible printed circuit. The method includes applying a coverlay over at least one surface of the flexible printed circuit, wherein the coverlay is patterned to not cover any components attached to the surface of the flexible printed circuit. The coverlay at least in part forms an essentially planar surface of the flex inlay.

A circuit layer is formed by drilling vias and forming channels in a circuit layer which has catalytic particles exposed on the surfaces, channels, and vias. A first flash electroless deposition is followed by application of dry film, followed by selective laser ablation of the dry film channels and vias. A second electroless solution is applied which provides additional deposition over the first flash electroless deposition but only on the vias and trace channel areas. An electrodeposition follows, using the first deposition as a cathode. The dry film is stripped and the first electroless layer is etched, leaving only depositions in the channels and vias.

A dielectric substrate may support conductive traces that form windings for a least one pole of a planar armature of an axial flux machine. At least a portion of the dielectric substrate, which is adapted to be positioned within an annular active area of the axial flux machine, may include a soft magnetic material. Such a planar armature may be produced, for example, by forming the conductive traces on the dielectric substrate, and filling interstitial gaps between the conductive traces with at least one epoxy material in which the soft magnetic material is embedded.

A resin composition includes: a resin as Component (A); and an inorganic filler as Component (B). The Component (B) includes anhydrous magnesium carbonate as Component (b1) and aluminum oxide as Component (b2). Content of the Component (b1) falls within a range from 35% by volume to 65% by volume relative to 100% by volume of the Components (b1) and (b2) combined. Content of the Component (B) falls within a range from 60% by volume to 75% by volume relative to 100% by volume of the resin composition.

According to one embodiment, a metal base circuit board includes a metal base substrate, a first circuit pattern, and a first insulating layer between the metal base substrate and the first circuit pattern. The first insulating layer covers a lower surface of the first circuit pattern and at least part of a side surface of the first circuit pattern, the lower surface facing the metal base substrate, the at least part of the side surface being adjacent to the lower surface.

A metal-clad laminate includes: an insulating layer; and a metal layer stacked on the insulating layer. The insulating layer includes: a first layer; and a second layer interposed between the first layer and the metal layer. The first layer contains a cured product of a first resin composition containing composite particles. The second layer contains a cured product of a second resin composition. The first resin composition contains composite particles, each having a core containing a fluororesin and a shell containing a silicon oxide that coats the core at least partially. The second resin composition may or may not contain composite particles. When the second resin composition contains the composite particles, a ratio of the composite particles in the second resin composition to solid content of the second resin composition is lower than a ratio of the composite particles in the first resin composition to solid content of the first resin composition.

A printed circuit board according to an embodiment includes a first insulating layer; a first circuit pattern disposed on a lower surface or inside the first insulating layer; a second circuit pattern disposed on an upper surface of the first insulating layer; a second insulating layer disposed on the upper surface of the first insulating layer and surrounding the second circuit pattern; and a protective layer disposed on an upper surface of the second insulating layer, wherein the second insulating layer has at least one recess formed on its upper surface, and wherein the protective layer is disposed in the recess formed on the upper surface of the second insulating layer.

Provided are a polymer film including a particle A having a constricted structure and a polymer B; a laminate including the polymer film and a metal layer or metal wire disposed on at least one surface of the polymer film; and a method of producing the polymer film.

A printed wiring board includes a resin insulating layer including resin and particles, and a conductor layer formed on a surface of the resin insulating layer. The particles in the resin insulating layer include first particles and second particles such that the first particles are partially embedded in the resin and the second particles are completely embedded in the resin, and the resin insulating layer is formed such that the first particles has exposed surfaces exposed from the resin and covered surfaces covered by the resin, respectively, the surface of the resin insulating layer includes the first exposed surfaces, and a ratio of a second area to a first area is in a range of 0.1 to 0.25 where the first area is an area of the surface of the resin insulating layer, and the second area is obtained by summing areas of the exposed surfaces of the first particles.

A polybenzimidazole production method for producing the polybenzimidazole including a repeating unit represented by the following formula (1):

##STR00001##

wherein R.sup.f is —SO.sub.2—, —O—, —CO—, an alkylene group optionally containing a substituent, or a group represented by the following formula (a):

##STR00002##

two Xs are each individually a hydrogen atom or a monovalent organic group; and R.sup.1 is a divalent organic group, the production method including a step (1-1) of polymerizing a tetramine compound and a dicarboxylic acid derivative compound to provide a polybenzimidazole precursor polyamide, and a step (1-2) of dehydrocyclizing the polybenzimidazole precursor polyamide.