Abstract: A bow-spring centralizer includes a center assembly having a plurality of bow springs and a pair of generally tubular moving collars secured one to each end of each bow spring, the center assembly formed intermediate a pair of generally tubular stop collars. Each moving collar/stop collar combination forms an interlocking and axially extendable collar. The centralizer is formed from a single tube. The tube is cut using a laser according to a cut pattern that creates interlocked stop collar/moving collar combinations that are rotatably locked but axially movable one relative to the other. Each of the interlocked stop collars and moving collars includes a plurality of circumferentially spaced heads, each head integrally formed on one of a plurality of circumferentially spaced extensions protruding from the stop collar or moving collar. The heads may have a variety of projected shapes, such as a rectangular, arrow or a teardrop shaped.

Abstract: A flow control apparatus (100) for controlling the inflow of production fluids (134, 140) from a subterranean well includes a tubular member (118) having at least one opening (138) that allows fluid flow between an exterior of the tubular member (118) and an interior flow path of the tubular member (118) and a flow restricting device (120) operably positioned in a fluid flow path between a fluid source and the at least one opening (138). The flow restricting device (120) includes a valve (128, 130) and an actuator (126). The actuator (126) includes a material that swells in response to contact with an undesired fluid (140), such as water or gas. The flow restricting device (120) is operable to autonomously reduce the fluid flow through the flow control apparatus (100) in response to contact between the material and the undesired fluid (140).

Abstract: A technique is provided for creating a well screen having a diffusion layer affixed to a filter medium to create a coherent structure. The diffusion layer is formed as a structure that freely allows movement of fluid, while the filtering medium is designed to filter particulates of a specific size. The diffusion layer is affixed to the filtering medium along a filtering medium surface to greatly improve collapse and burst resistance of the filtering medium. One method of affixing comprises bonding the diffusion layer to the filtering medium via a sintering process.

Abstract: A wellbore screen (1) is provided for controlling inflow of solid particles into a wellbore (2). The wellbore screen comprises a conduit (3) for transporting fluid, an outer layer (4) comprising a filter for reducing inflow of solid particles into the conduit (3), the outer layer extending around the conduit and being radially expandable against the wellbore wall, and swelling means arranged between the conduit and the outer layer. The swelling means (6) is susceptible of swelling upon contact with a selected fluid so as to radially expand the outer layer against the wellbore wall.

Abstract: A method for in situ heating of an organic-rich rock formation is provided. Preferably the organic-rich rock formation comprises kerogen. The method may include the steps of providing a first wellbore extending at least to a depth of the organic-rich rock formation, and providing a second wellbore also extending to a depth of the organic-rich rock formation and intersecting the first wellbore. The method may also include injecting air and a combustible fuel into the first wellbore, and providing a downhole burner in the wellbore so as to cause the air and the combustible fuel to mix and to combust at substantially the depth of the organic-rich rock formation. The method may further include, circulating combustion products into and up the second wellbore such that a pyrolysis zone is created from the first wellbore and second wellbores that provides substantially complete pyrolysis of the organic-rich rock formation between the first wellbore and the second wellbore.

Abstract: Apparatus and methods of reducing the viscosity of a gelled fluid is provided. In one embodiment, a viscosity reducing microbe is disposed in a capsule and added to the gelled fluid. The gelled fluid may include a thickening agent adapted to increase its viscosity. Upon release from the capsule, the microbe begins to digest the thickening agent in the gelled fluid and/or releases enzymes that that breakdown the thickening agent.

Abstract: A composite proppant having a proppant substrate such as a porous ceramic or silica sand coated with magnetic particles and a method of propping a subterranean formation using a composition consisting essentially of the composite proppant.

Abstract: An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured valving member with curved and flat portions that alternatively direct fluid flow through a bore or opening in the valving member via an inner channel or around the periphery of the valving member in an outer channel. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation.

Abstract: The present invention includes a method and system for heat management in an oil field, the method including the steps of, on a first time interval: determine a thermal maturity for each subsurface region associated with a pattern of oil wells in the oil field, input the thermal maturity output from step (a)(i) and determine a latent heat target and steam injection target for each subsurface region; and input the latent heat target and steam injection target output from step (a)(ii) and a subsurface region development plan and recalibrate a steam optimizer policy engine, on a second time interval: using the recalibrated steam optimizer policy engine from step (a)(iii) and operating data, determine steam injection schedules; and collect operating data; and on a third time interval: input the thermal maturity output from step (i) and perform a periodic look-back process, thereby producing deviations from latent heat targets; and input the deviations from latent heat targets from step (c)(i) and re-determine the

Abstract: Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200° C. and 240° C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

Abstract: An embodiment is a portable, modular apparatus, having one or more modules, for recovering oil from an oil well and generating electric power, and including a chassis to support a fuel reformer, a gas separator, a power generator, and/or a compressor. The fuel reformer module is adapted to react a fuel source with water to generate driver gas including a mixture of carbon dioxide gas and hydrogen gas. The gas separator module is operatively coupled to the reformer module and is adapted to separate at least a portion of the hydrogen gas from the rest of the driver gas. The power generator module is operatively coupled to the gas separator module and is adapted to generate electric power using a portion of the separated hydrogen gas. The compressor module is operatively coupled to the reformer module and is adapted to compress a portion of the driver gas, and to eject the driver gas at high pressure into the oil well for enhanced oil recovery.

Abstract: Flexible riser, comprising a length of a flexible pipe with an upper end, a bend restrictor and a termination for hanging up on a vessel, a floating installation or a platform, distinguished in that the bend restrictor in the upper end is connected to an adapter pipe extending from a lower end at the bend restrictor to an upper end, to an end coupling to which the upper ends of both the flexible pipe and the adapter pipe are fastened, the flexible riser extending through the bend restrictor and the adapter pipe and the end connection comprising a means for hanging up at deck level of the vessel, the installation or the platform. Method for pulling-in and banging up of the flexible riser.

Abstract: Apparatus, methods, and systems for extracting oil or natural gas from a well using a portable coal reformer. In one example, the method may include reforming coal by reaction with water to generate driver gas (comprising carbon dioxide and hydrogen gas), and injecting the driver gas into the well. The driver gas reduces the viscosity and pressurizes the oil to help extract the oil from the oil well. The coal reforming operation may include combusting coal or other combustible material with ambient oxygen to release energy, and heating coal and water with the energy released to a temperature above that required for the coal reforming reaction to proceed, thereby reforming coal and water into driver gas. The driver gas may be purified by filtering out particles and sulfur before injecting into the well. A portion of the hydrogen gas may be separated from the driver gas and used to generate electrical power.

Abstract: A pump has a housing having a top plate and a bottom plate and a shaft slidingly extending through an aperture in the top plate. A piston is connected to the shaft. The piston separates a volume within the housing into a first stage chamber defined in the housing below the piston and a second stage chamber defined in the housing above the piston. A fluid transfer port in the piston is in fluid communication with the second stage chamber and, through a check valve, with the first stage chamber. Another stage check valve allows one-way flow of fluid from a suction area below the bottom plate into the first stage chamber. A pressure control valve may be provided for selectively allowing fluid to flow out of the first stage chamber.

Abstract: An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured valving member with curved and flat portions that alternatively direct fluid flow through a bore or opening in the valving member or around the periphery of the valving member.

Abstract: A technique is provided for treating a plurality of well zones with a service tool during a single trip downhole. The service tool is run downhole to a selected well zone that is isolated for treatment. Following treatment of the well zone, the service tool is moved to a subsequent well zone isolated for treatment. When the lengths of the well zones to be treated are dissimilar, the active length of the service tool can be adjusted to correspond with the well zone length to optimize the well treatment operation.

Abstract: A close-tolerance expandable bow spring centralizer 8 having a first expandable collar 10A coupled to and spaced apart from a second expandable collar 10B through a plurality of bow springs 30 wherein expandable collars 10A, 10B comprise a plurality of slidably coupled links 16 that separate to expand the diameter of the collars 10A, 10B, e.g., upon expansion of an expandable pipe string 80 on which the centralizer 8 is received. Expandable bow spring centralizer 8 may grip the expandable pipe string 80 when in the collapsed configuration to eliminate the need for a stop collar. Additionally or alternatively, a fin 32 may be connected to each bow spring 30, and then connected to one or more adjacent fins 32 upon collapse of the bow springs 30 to form a restraining band 39 that may be ruptured, e.g., upon expansion of the expandable pipe string 80.

Abstract: A method for increasing oil recovery from an oil reservoir in which method surplus gas streams from a plant for synthesis of higher hydrocarbons from natural gas is injected into the reservoir, is described. The surplus streams from the plant is the tailgas from the synthesis and optionally nitrogen from an air separation unit which delivers oxygen or oxygen enriched air to the plant for synthesis of higher hydrocarbons.

Abstract: A Liquid Nitrogen Enabler Apparatus is disclosed herein, wherein the apparatus may be configured to protect the earth, people and property. The apparatus is configured to distribute liquid nitrogen that converts to nitrogen gas to achieve its desired effects. Nitrogen gas carries the temperature, the inertness, and the tendency to cloud, gather amongst itself with the exclusion of other gases. Combining the thermal qualities with the inertness of the nitrogen gas, fires and other such crises are handled. There are various advantages associated with treating fires and other such crises with liquid nitrogen such as that when the liquid nitrogen converts into a gaseous form and is applied to a fire draft, rather than directly to the fire itself. The fire draft will pull the gaseous nitrogen into the fire, thus ending the burn.

Abstract: In one aspect of the present invention, a roller assembly on an excavator for degrading natural and man-made formations has a plurality of pointed inserts disposed along its outer diameter. The inserts have a tip adapted to impact the formation and at least one of the tips has polycrystalline diamond bonded to a cemented metal carbide segment. The diamond also has a substantially conical geometry with a 0.50 to 0.200 inch radius and a thickness greater that 100 inches at the apex. The diamond also has a volume that is 75 to 150 percent of a volume of a carbide substrate.

Abstract: A mulcher apparatus includes a tractor and a mulcher unit provided to the tractor. The mulcher unit includes a tooth assembly with a holder and a cutter element with a cooperating notch portion and cross bar arrangement. The notch portion can be retrofit to existing holder arrangements. The cutter element may include various features, to enhance cutting efficiency. For example, the cutter elements may include a double-ended structure, a relatively wide serrated cutting edge at one or both ends, carbide coatings, layers or inserts, etc.

Abstract: A striking device of a power tool includes a striking room, two striking blocks and a transmission shaft. The striking room has a pivotal restricting groove at its two sides respectively, and two supporting surfaces formed adjacent to two sides of the pivotal restricting groove. Each striking block has a projected pivot formed axially, pivotally installed between two pin holes of the striking room via two pins. Two sides of the projected pivot are extended with striking portions, and the transmission shaft has two restricting blocks provided with a struck segment and a displacing segment. When one of the striking portion strikes one of the struck segments, the other of the striking portions just leans on the supporting surface to activate the transmission shaft to rotate. When the striking portion moves away after striking, it passes through the corresponding displacing segment to carry out next strike.

Abstract: A compact pneumatic hand tool having a cylinder assembly received in a space of a body, wherein, the bottom inlet opening of the cylinder assembly is communicated with the air inlet in the space, meanwhile, the rear inlet passage of the cylinder assembly is corresponded to the control knob mounting portion of the body. Moreover, a control knob is extended through the control knob mounting portion of body as well as the rear inlet passage of the cylinder assembly, and a rotor of the cylinder assembly is coupled with a second coupling portion of a striking assembly. In addition, the front opening of the body is covered with the front cap and a sealing pad is provided between the body and the front cap, meanwhile the central axle is extended out of the front cap.

Abstract: A hand-held power tool a percussion mechanism (2) of which includes a percussion piston (4) displaceable by an air spring (3) of the power tool for applying blows to an anvil (5) that is dust-tightly and lubricant-tightly sealed with respect to its guide by two axially offset sealing elements (8) between which a lubricant chamber (9) for receiving a barrier lubricant (10) is formed.

Abstract: The invention relates to a hand tool machine (2), in particular a drilling and/or percussion hammer, with a housing (4) and a vibration-damped handle (10) elastically supported relative to the housing (4) with two essentially parallel legs (20, 22) and a coupling element (44 or 46) between each leg (20 or 22) and the housing (4) that is pin-jointed to the leg (20 or 22) and the housing (4). The coupling elements (44, 46) are connected to each other by a connector (48) that synchronizes the movements of the coupling elements (44, 46).

Abstract: A device and method for variable torque fastening are capable of easily varying a tightening torque and are capable of automatically changing a tightening torque according to the sequence set by an operator. The variable torque fastening device includes a fastening unit having a drive shaft which is rotated by a motor, a driven shaft which is rotated by the drive shaft and is mounted with a fastening tool, a slip clutch which intermittently connects the drive shaft to the driven shaft, and a piston which moves forward and backward by an air pressure to press the slip clutch, a compressed air supply source which supplies compressed air to the fastening unit to press the piston, and an air pressure control unit which controls a pressure of the air that presses the piston.

Abstract: An air tool is composed of a main rod, a sleeve, a compression spring and a connector. The main rod possesses a plugging bar, a blocking annular surface, and a through bar having a connecting portion in its end portion. The through bar is mounted with the compression spring and inserted in the sleeve. The sleeve has a blocking annular surface to block the compression spring. The connector is screwed with the end of the main rod. In addition, via the elastic counterforce of the compression spring, the impact of the air tool generated while operating the air tool can be weakened so as to prevent the air tool from being damaged and enable a user to hold the air tool easily.

Abstract: It is an object of the invention to provide a technique that contributes to rationalization of a mechanism relating to reduction of vibration in an impact tool. Representative impact tool includes a tool body, a hammer actuating member, a dynamic vibration reducer and a positioning elastic element. The positioning elastic element contacts the hammer actuating member and thereby positions the tool body with respect to the workpiece so as to absorb a reaction force caused by rebound from the workpiece and acts on the hammer actuating member when the hammer actuating member performs the hammering operation on the workpiece. The positioning elastic element includes the elastic element formed as a component part of the dynamic vibration reducer.

Abstract: It is an object of the invention to provide an effective technique for further enhancing the effect of reducing a reaction force inputted during hammering operation. Representative impact tool comprises a tool body, a hammer actuating member, a cylinder and a compression coil spring. The compression coil spring contacts the hammer actuating member and thereby positions the tool body with respect to the workpiece when the hammer actuating member is pressed against the workpiece and pushed rearward in advance of the hammering operation. In such position, the compression coil spring absorbs a reaction force that is caused by rebound from the workpiece and acts upon the hammer actuating member when the hammer actuating member performs the hammering operation on the workpiece. The cylinder is inserted into the tool body from the front along the axial direction of the hammer actuating member and thereby housed within a predetermined housing part of the tool body.

Abstract: A tool for installing various configurations of electrical boxes to framing studs during building construction includes a staff having graduations indicating distances from an end of the staff. A mounting fixture is slidably disposed on the staff and can be secured at a desired position along the length of the staff corresponding to a desired installation height for the electrical boxes. The mounting fixture may include pins for engaging apertures on an electrical box, and magnets for magnetically engaging metal electrical boxes, to help retain the electrical boxes on the mounting fixture during installation.

Abstract: Carbon nanotube-based devices that can be used to meet the growing miniaturization and performance needs of electronic systems, are provided. In particular, a transmission line and inductor that include nanotube bundles is disclosed. In a further embodiment a method for isolating nanotubes with proteins is disclosed. In another embodiment a nanoswitch using nanotubes is disclosed. In a final embodiment a low loss, high permeability material is disclosed that includes a conductive coil and a set of nanotube toroids.

Abstract: In a ground cable to be applied to an on-vehicle wiring harness or the like, the aim is to make it easy and simple to conduct the waterproofing work. A first sealant 6 of the UV-cure type having as a contact angle with respect to the bare conductor 1a of the ground cable 1 an acute one and a viscosity of 15-500 mPa·s is delivered by drops onto the bare conductor. The first sealant 6 is delivered by drops onto a second sealant 7. The first and second sealants 6 and 7 are irradiated by ultraviolet rays. This permits the first sealant 6 to, without the need to suck-decompress the interior of the ground cable 1, by dint of capillarity, spontaneously permeate into the cable core 1b of the ground cable 1 to be then cured. Even in case where a ground terminal 2 has a pair of ground cables 1 crimped thereonto, each ground cable 1 permits an adequate amount of the sealant 6 to, with ease, permeate it.

Abstract: Systems and methods of nanomaterial transfer are described. A method of nanomaterial transfer involving fabricating a template and synthesizing nanomaterials on the template. Subsequently, the nanomaterials are transferred to a substrate by pressing the template onto the substrate. In some embodiments, the step of transferring the nanomaterials involves pressing the template onto the substrate such that the nanomaterials are embedded below a surface layer of the substrate. In some embodiments, the temperature of the plurality of nanomaterials is raised to assist the transfer of the nanomaterials to the substrate.

Abstract: The invention concerns a protective sheath against radiation, in particular derived from electric field generated by electric cables (1, 2, 3) extending inside the sheath. The invention is characterized in that it comprises an electrically insulating plastic outer layer (4) covering an electrically conductive material layer (5), the sheath end including removable connecting means for connecting the electrically conductive material layer (5) to an electrical conductor (7) designed to be connected to the ground, said sheath enclosing or designed to enclose at least one neutral cable (1), one ground cable (2) and one phase cable (3) connected to an electric power distribution system.

Abstract: FEP compositions are provided that provide foam insulation in coaxial cable that surpasses the return loss obtained when PFA is used to make the foamed insulation, one composition comprising a blend of tetrafluoroethylene/hexafluoropropylene copolymers, one of said copolymers exhibiting a strip force of at least about 3 lbf (13.3 N) and another of said copolymers exhibiting a strip force no greater than about 2.5 lbf (11.1 N), said blend exhibiting a strip force of at least about 3 lbf (13.3 N), each said strip force being the force necessary to break adhesion between conductor and said one of said copolymers, said another of said copolymers, and said blend, respectively, and another composition comprising tetrafluoroethylene/hexafluoropropylene copolymer having an MFR of no greater than about 16 g/10 min and containing —CF3 end groups and an effective amount of wire affinity end groups to exhibit a strip force of at least about 3 lbf (13.

Abstract: Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.

Abstract: The present invention relates to a semiconductive composition and a power cable using the same. The semiconductive composition according to the present invention constituting a semi-conductive layer of a power cable includes 100 parts by weight of a base resin composed of an ethylene-based copolymer resin; 45 to 70 parts by weight of a carbon black; and 0.2 to 5.0 parts by weight of a nonionic surfactant. The semiconductive composition according to the present invention has an improved interfacial smoothness in the semiconductive layer and the insulation layer of the power cable and an increased dielectric breakdown strength of the insulation layer. Also, the semiconductive composition according to the present invention may be useful to ensure an easy cleaning property of a mold upon extruding/molding a power cable.

Abstract: A multi-pair cable having a plurality of twisted conductor pairs. The twisted conductor pairs each have an initial lay length that is different from that of the other twisted conductor pairs. The plurality of twisted conductor pairs defines a cable core. The core is twisted at a varying twist rate such that the cable core has a mean lay length of less than 2.5 inches.

Abstract: A method for electroless plating of metal on a laser-patterned substrate. A substrate is provided on which both a thermal imaging layer and catalytic layer are deposited. On exposure to a laser beam, sufficient levels of radiation are converted to heat in the thermal imaging layer to render the exposed regions of the adjacent catalytic layer inactive. The laser-patterned substrate is then exposed to a reaction solution which initiates the growth of a metal film on the unexposed regions of the catalytic layer.

Abstract: A wiring board and a method of forming a wiring board including a first substrate, a second substrate having a smaller mounting area than a mounting area of the first substrate, and a base substrate laminated between the first substrate and the second substrate such that the first substrate extends beyond an edge of the second substrate. An IVH (Interstitial Via Hole) penetrates the base substrate.

Abstract: A wiring board 100 has a multilayer structure in which insulating layers and wiring layers are arranged on upper and lower surfaces of a core substrate 240, and has a via structure 200 in which electrolytic Cu plating is carried out over a via forming opening provided by patterning a resist layer to form a via 220. A through hole 244 and a wiring pattern 210 to be connected to the through hole 244 are formed on the core substrate 240. The via 220 taking a cylindrical shape is mounted on an upper surface of the wiring pattern 210 and a wiring pattern 230 is formed on an upper surface of the via 220. The via structure 200 is constituted by the wiring pattern 210, the via 220 and the wiring pattern 230, and the through hole 244, the wiring pattern 210, the via 220 and the wiring pattern 230 are electrically connected respectively.

Abstract: The present invention is directed to a substrate for subsequent eutectic bonding with a subsequently applied metal to provide, or as a precursor to the provision of, a circuit substrate. The circuit substrate comprises a dielectric film and a layer of an oxide or oxides of a metal on the film. The metal oxide layer has been formed by sputtering the metal of the metal oxide or oxides onto a surface of the film in the presence of an inert atmosphere save for at least one reactive gas content to provide the oxygen of the oxides.

Abstract: A composite ceramic substrate includes a ceramic substrate having surface-mounted components mounted thereon, external terminal electrodes connecting wiring patterns disposed on the ceramic substrate and surface electrodes of a motherboard, and a convex leg portion made of resin and arranged such that an end surface supports the external terminal electrodes, and the external terminal electrodes are connected to the wiring patterns via a via-hole conductor provided in the leg portion.

Abstract: To provide a method for connecting printed circuit boards with high connection reliability, while avoiding the problem of shorting even with a fine pitch. A method for connecting printed circuit boards (PCB) containing metal wiring, or connecting a printed circuit board (PCB) containing metal wiring with a metal lead wire or a metal contact, which method includes a step of thermocompression bonding of an adhesive film with connectors, the adhesive film being composed of an adhesive composition comprising a thermoplastic resin and organic particles, wherein the viscosity decreases as the applied thermocompression force increases at a temperature of 100-250° C.

Abstract: A multilayer ceramic substrate includes a plurality of ceramic layers laminated each other. The plurality of ceramic layers form a bulge and a cavity having such a shape that an opening area of the cavity gradually becomes smaller toward a bottom of the cavity.

Abstract: Through holes 36 are formed to penetrate a core substrate 30 and lower interlayer resin insulating layers 50, and via holes 66 are formed right on the through holes 36, respectively. Due to this, the through holes 36 and the via holes 66 are arranged linearly, thereby making it possible to shorten wiring length and to accelerate signal transmission speed. Also, since the through holes 36 and the via holes 66 to be connected to solder bumps 76 (conductive connection pins 78), respectively, are directly connected to one another, excellent reliability in connection is ensured.

Abstract: An object of the present invention is to provide a material for forming a capacitor layer comprising a dielectric layer formed by any one of a sol-gel method, an MOCVD method, and a sputtering deposition method. The material can reduce a leakage current of a capacitor circuit. In order to achieve the object, a material for forming a capacitor layer comprising a dielectric layer between a first conductive layer to be used for forming a top electrode and a second conductive layer to be used for forming a bottom electrode, characterized in that the dielectric layer is a dielectric oxide film formed by any one of a sol-gel method, an MOCVD method, and a sputtering deposition method; and particles constituting the dielectric oxide film are impregnated with a resin component is employed.

Abstract: A wiring board connection method connects wiring boards each having a strip-shaped connection terminal for connecting with another substrate, the method including the steps of: aligning the wiring boards so that the connection terminals face each other with a fluid interposed therebetween; and bonding the connection terminals with each other by heating and then-cooling the fluid, wherein: the fluid is a material that generates air bubbles upon being heated; a plurality of the connection terminals are provided on each of the wiring boards; and a groove is formed in each of at least one of the connection terminals in at least one of the wiring boards, the groove extending across the relevant connection terminal.

Abstract: A circuit arrangement comprising a set of signal layers, a set of first power layers, a set of second power layers, a set of signal vias, a set of first power vias, a set of second power vias, wherein a signal via of the set of signal vias provides a signal path for a high-frequency (HF) signal current, wherein at least a power via of the set of first power vias and at least a power via of the set of second power vias provide return paths for return currents associated with the signal current, wherein the return path provided by the power via of the set of second power vias is connected with a power layer of the set of second power layers, wherein at least one power layer of the set of first power layers is arranged between the power layer of the set of second power layers and each signal layer of the set of signal layers.

Abstract: A printed circuit board includes a base insulating layer, first to third signal lines, a first cover insulating layer and a conductive layer. Wide parts are formed in the first to third signal lines. The first cover insulating layer is provided on the base insulating layer so as to cover the wide parts. The conductive layer is provided on the first cover insulating layer so as to cover a portion above the wide parts.