A method for fabricating a circuit board comprises preparing an elastomeric substrate having a roughened surface. The elastomeric substrate is stretched before an electrically conductive material is electrolessly deposited onto the roughened surface. A suitable amount of electrically conductive material is deposited onto the elastomeric substrate before the elastomeric substrate is released from its stretch.

A liquid crystal polymer film that includes: a benzene ring; a naphthalene ring; and a carboxymethyl group, wherein, in a .sup.13C-NMR spectrum of a liquid crystal polymer film decomposed with supercritical methanol, an integral value CA of a peak derived from the benzene ring, an integral value CB of a peak derived from the naphthalene ring, and an integral value CC of a peak derived from the carboxymethyl group satisfy (CA+CB)/CC of 1.35 to 1.65.

A multi-layer coating on an outer surface of a substrate includes a first layer applied directly to the outer surface of the substrate. The first layer includes diamond-like carbon (DLC) configured to mitigate metal whisker formation. A second layer is applied on a top surface of the first layer. The second layer is a conformal coating that includes a second material configured to bind to the top surface of the first layer and fill any microfractures that may form in the first layer. Optionally, a third layer is applied on a top surface of the second layer and includes DLC configured to protect the second layer from oxidation and degradation.

In an x-ray source, an isolation circuit can isolate bias voltage at a cathode from a bias voltage at an alternating current source (AC source). The isolation circuit can transfer alternating current from the AC source to the cathode. The isolation circuit can be made repeatedly with minimal variation or failed parts, can be light, and can be small. The isolation circuit can include planar transformer(s). Each planar transformer can include a primary trace on a primary circuit board and a secondary trace on a secondary circuit board. The primary trace and the secondary trace can each include a spiral shape. The primary trace can be located in close proximity to the secondary trace such that alternating electrical current through the primary trace will induce alternating electrical current through the secondary trace.

Embodiments described herein can include multi-layer circuits within a liquid crystal polymer (LCP) material to define a 3-D interconnect structure that connects the microelectronics features, devices, components and electrical interfaces. In addition, mechanical functions can be embedded in a fashion and proximity such that the embedded electronics can interface and interact with each other as well as introduced conditions relevant to the function of the device and the outside world or environment it is exposed to.

A circuit board structure includes a dielectric substrate, at least one embedded block, at least one electronic component, at least one first build-up circuit layer, and at least one second build-up circuit layer. The dielectric substrate includes a through cavity penetrating the dielectric substrate. The embedded block is fixed in the through cavity. The embedded block includes a first through hole and a second through hole. The electronic component is disposed in the through hole of the embedded block. The first build-up circuit layer is disposed on the top surface of the dielectric substrate and covers the embedded block. The second build-up circuit layer is disposed on the bottom surface of the dielectric substrate and covers the embedded block.

A method of manufacturing a multilayer board includes forming conductor patterns on four or more insulating base material layers, forming a multilayer body by stacking the insulating base material layers in a state in which the conductor patterns face each other with prepreg layers therebetween, and heat-pressing the multilayer body. In a state before the step of heat-pressing, among the prepreg layers, a thickness of an outermost prepreg layer is larger than a thickness of a prepreg layer other than the outermost prepreg layer.

The present strain gauge includes a substrate having flexibility; a resistor formed from a material containing at least one of chromium and nickel, on the substrate; a pair of wiring patterns formed on the substrate and electrically connected to both ends of the resistor; and a pair of electrodes formed on the substrate and electrically connected to the pair of wiring patterns, respectively. The wiring patterns include a first layer extending from the resistor, and a second layer having a lower resistance than the first layer and layered on the first layer. On the substrate, an electronic component mounting area is demarcated, on which an electronic component electrically connected to the electrodes is mounted.

A resin multilayer substrate includes a multilayer body including resin base-material layers in a thickness direction, a side-surface conductor on at least a side surface of the multilayer body and made of a metallic material with a coefficient of thermal expansion whose difference from a coefficient of thermal expansion of the resin base-material layers in a plane direction is smaller than a difference from a coefficient of thermal expansion of the resin base-material layers in the thickness direction, a circuit component in the multilayer body and defining a circuit, and inner conductors in the multilayer body, located between the side-surface conductor and the circuit component along the side-surface conductor, and at least partially overlapping each other when viewed in the thickness direction, each of the inner conductors being one of a dummy conductor and a ground conductor.

Provided are a liquid crystal polymer (LCP) film and a laminate comprising the same. The LCP film has a first surface and a second surface opposite each other, and a Kurtosis (Rku) of the first surface ranges from 3.0 to 60.0. With the Rku, the LCP film is able to improve the peel strength with a metal foil and ensure that a laminate comprising the same maintains the merit of low insertion loss.