Tamper-respondent assemblies are provided which include a circuit board, an enclosure assembly mounted to the circuit board, and a pressure sensor. The circuit board includes an electronic component, and the enclosure assembly is mounted to the circuit board to enclose the electronic component within a secure volume. The enclosure assembly includes a thermally conductive enclosure with a sealed inner compartment, and a porous heat transfer element within the sealed inner compartment. The porous heat transfer element is sized and located to facilitate conducting heat from the electronic component across the sealed inner compartment of the thermally conductive enclosure. The pressure sensor senses pressure within the sealed inner compartment of the thermally conductive enclosure to facilitate identifying a pressure change indicative of a tamper event.

A capacitor device to store electrical charge is disclosed that includes a first unit of a first conductor layer fabricated from a first material. The first conductor layer is sandwiched between two dielectric layers. This assembly is layered on a second unit of a second conductor layer fabricated from a second material and sandwiched between two additional dielectric layers. The first conductor layers are all electrically connected to one another, and the second conductor layers being electrically connected to one another but are not electrically connected to the first conductor. Any multiple of first and second units may be utilized.

The present application relates to an electromagnetic band-gap, a directional antenna including same, and a use thereof. The electromagnetic band-gap structure and the directional antenna including same, of the present application, are lightweight and small in size, and can have excellent directivity. In addition, the electromagnetic band-gap structure and the directional antenna including same can be used for aviation electronic equipment and portable measurement equipment.

A printed circuit board includes: a first layer including a first ground including a first opening, wherein a first ground wire is within the first opening; a second layer disposed in a direction from the first layer and including a second ground including a second opening, wherein the second opening at least partially overlaps with the first opening and wherein a second ground wire is within the second opening; a third layer between the first layer and the second layer and including a third opening, wherein the third opening at least partially overlaps with the first opening and wherein a first via pad is within the third opening; and a fourth layer between the second layer and the third layer and including a fourth opening, wherein the fourth opening at least partially overlaps with the third opening and wherein a second via pad is within the fourth opening.

The present application discloses a differential signal routing line of a circuit board and a circuit board, which comprises a circuit board, and the circuit board is provided with differential signal routing lines including a first differential signal routing line and a second differential signal routing line that are disposed at different layers of the circuit board.

Technologies directed to coupling structures for antenna feeds of phased array antennas are described. One circuit board includes a first layer with a first portion of a RF coupling structure, a second layer with a second portion of the RF coupling structure, and a first insulation layer located between the first layer and the second layer. The RF coupling structure is configured to electromagnetically couple a first conductive trace on the first layer and a second conductive trace on the second layer at RF frequencies. The circuit board also includes an RF shielding structure coupled to a ground connection on the second layer and located in the first insulation layer. The RF shielding structure is configured to operate as a RF short circuit between the ground connection and a third conductive trace on the first layer at RF frequencies.

An element assembly has a structure in which insulator layers including first and second insulator layers are laminated in an up-down direction. The first insulator layer is above the second insulator layer. A radiant conductor layer is on an upper surface of the first insulator layer. A first capacitance defining portion includes a first interlayer connection conductor passing through one or more of the insulator layers in the up-down direction. The first interlayer connection conductor is electrically connected to the radiant conductor layer. The radiant conductor layer, a ground conductor, and the first capacitance defining portion define and function as a patch antenna. When the first interlayer connection conductor is electrically connected to the radiant conductor layer, a distance from a lower end of the first interlayer connection conductor to the ground conductor in the up-down direction is shorter than a distance from the radiant conductor layer to the ground conductor in the up-down direction.

A hard disk drive flexible printed circuit (FPC) includes a plurality of fingers extending from a main portion, with each finger having a first wiring layer including a first electrically conductive trace layout, a second wiring layer including a second electrically conductive trace layout, and a base film interposed between the first and second wiring layers, where the first conductive trace layout includes at least one thermally conductive protective island overlaying a respective portion of the second trace layout to provide a protective thermal barrier to the base film. Hence, maximum temperatures across various layers of the FPC laminate can be reduced, damage to the FPC prevented, and manufacturing yields improved.

A wiring circuit board includes an insulating layer, a pair of wiring layers, an insulating layer, and a wiring layer. The pair of wiring layers are disposed on the insulating layer and extend side by side apart from each other. The insulating layer is disposed on the insulating layer so as to cover the pair of wiring layers. The wiring layer is disposed on the insulating layer and extends along the pair of wiring layers, while facing to the pair of wiring layers in a thickness direction of the wiring layer. The wiring layer has a ridge portion. The ridge portion protrudes into the insulating layer toward a region between the wiring layers and extends along the region.

A filter includes a first input/output electrode and the second input/output electrode, and is arranged on a first main surface of a mounting substrate. The mounting substrate includes a first land electrode, a second land electrode, a ground terminal, and a plurality of via conductors. The first land electrode is connected to the first input/output electrode. The second land electrode is connected to the second input/output electrode. The ground terminal is located closer to a second main surface side than the first main surface in a thickness direction of the mounting substrate. The plurality of via conductors is arranged between the first main surface and the second main surface, and is connected to the ground terminal. The plurality of via conductors is located between the first land electrode and the second land electrode in a plan view from the thickness direction of the mounting substrate.