A transmission line device includes a first multilayer substrate with a transmission line including laminated insulating base materials and a conductor pattern on the insulating base materials, and a second multilayer substrate defining a connected member to which the transmission line of the first multilayer substrate is connected. The conductor pattern includes a signal conductor pattern and a signal electrode pad electrically connected to the signal conductor pattern. The first multilayer substrate includes a resist film provided on a surface of a laminate of the insulating base materials, and the resist film includes an opening that is separated from an outer edge of the signal electrode pad in a surface direction of the laminate of the insulating base material and exposes the signal electrode pad.

A substrate for pattern formation, the substrate including at least a base material and a perfluoro(poly)ether group-containing silane compound-derived portion, wherein the base material includes at least one main face having a first region and a second region which is a region for pattern formation, adjacent to the first region, and the perfluoro(poly)ether group-containing silane compound-derived portion is disposed in the first region.

An electronic device such as a wearable electronic device may have a band. The band may form a stand-alone device or a strap for a wristwatch unit or other device. Electrical components may be mounted on flexible printed circuit substrates. A substrate may be encapsulated by elastomeric polymer material or other material forming the band. The elastomeric polymer material may form cavities that receive the electrical components. Components such as light-emitting diodes may be mounted to the flexible printed circuit substrates so that the light-emitting diodes are located in the cavities. Reflective sidewalls in the cavities may reflect light from the light-emitting diodes outwardly through a thinned portion of the band. Light-diffusing material in the cavities may be formed from clear polymer with light-scattering particles.

A semiconductor device includes a circuit board including an insulating layer having opposite front and rear surfaces, an electrode pad disposed on the front surface, a housing having an installation area for the circuit board, and a bonding material embedded in a recess within either a first area located at the rear surface of the insulating layer directly below an area of the circuit board in which the electrode pad is disposed, or at a second area located within the installation area of the housing and corresponding to the first area in a plan view.

A liquid solder resist composition contains a carboxyl group-containing resin, a photopolymerizable compound containing at least one compound selected from a group consisting of a photopolymerizable monomer and a photopolymerizable prepolymer, a photopolymerization initiator, and a titanium dioxide. The photopolymerization initiator contains a bisacylphosphine oxide-based photopolymerization initiator, a first -hydroxyalkyl phenone-based photopolymerization initiator that is a liquid at 25 C., and a second -hydroxyalkyl phenone-based photopolymerization initiator that is a solid at 25 C.

A substrate for pattern formation, the substrate including at least a base material and a perfluoro(poly)ether group-containing silane compound-derived portion, wherein the base material includes at least one main face having a first region and a second region which is a region for pattern formation, adjacent to the first region, and the perfluoro(poly)ether group-containing silane compound-derived portion is disposed in the first region.

A method for manufacturing a structure for embedding and packaging multiple devices by layer includes preparing a polymer supporting frame, mounting a first device in a first device placement mouth frame to form a first packaging layer, forming a first circuit layer and a second circuit layer, forming a second conductive copper pillar layer and a second sacrificial copper pillar layer, forming a second insulating layer on the first circuit layer, and forming a third insulating layer on the second circuit layer, forming a second device placement mouth frame vertically overlapped with the first device placement mouth frame, mounting a second device and a third device in the second device placement mouth frame to form a second packaging layer, forming a third circuit layer on the second insulating layer. A terminal of the second device and a terminal of the third device are respectively communicated with the third circuit layer.

A copper-clad laminate includes an insulating layer and a copper foil in contact with at least one surface of the insulating layer, in which the insulating layer contains a cured product of a resin composition containing a modified polyphenylene ether compound of which a terminal is modified with a substituent having a carbon-carbon unsaturated double bond, a chromium element amount on an exposed surface on which the insulating layer is exposed by an etching treatment of the copper-clad laminate with a copper chloride solution, measured by X-ray photoelectron spectroscopy is 7.5 at % or less with respect to a total element amount measured by X-ray photoelectron spectroscopy, and a surface roughness of the exposed surface is 2.0 m or less in terms of ten-point average roughness.

An etching method for manufacturing a substrate structure having a thick electrically conductive layer, and a substrate structure having a thick electrically conductive layer are provided. The etching method includes providing an electrically insulating substrate structure including a thermally conductive and electrically insulating layer, an electrically conductive layer, and a non-photosensitive polymer masking layer, removing one part of the non-photosensitive polymer masking layer and one part of the electrically conductive layer by a machining process to form at least one electrically conductive recess having the electrically conductive layer exposed, forming a predetermined thickness ratio between a thickness of the electrically conductive recess and a thickness of the electrically conductive layer, removing a reserved part of the electrically conductive layer between a bottom wall of the electrically conductive recess and a bottom surface of the electrically conductive layer, and removing a remaining part of the non-photosensitive polymer masking layer.

Described herein are systems and methods for creating a cavity within a substrate. The systems and methods may include passing a plasma gas over a first surface of the substrate. The plasma gas may include a reactant gas. The systems and methods also may include removing a portion of the substrate by reacting the reactant gas with a constituent of the first surface of the substrate, thereby forming the cavity.