Abstract: In the preferred embodiment, there is disclosed a printed circuit board having a surface providing a mating interface to which is electrically connected an electrical connector having signal conductors and ground conductors. The printed circuit board includes a plurality of stacked dielectric layers, with a conductor disposed on at least one of the plurality of dielectric layers. The mating interface includes a plurality of conductive vias aligned in a plurality of rows, with the plurality of conductive vias extending through at least a portion of the plurality of dielectric layers, at least one of the plurality of conductive vias intersecting the conductor. The plurality of conductive vias includes signal conductor connecting conductive vias and ground conductor connecting conductive vias.

Abstract: A circuit board disclosed in the present invention includes a core board on which a first circuit layer is placed, wherein the first circuit layer has a plurality of conductive pads; and at least one built-up structure covering the surface of the circuit board, which comprises a dielectric layer, a second circuit layer, and a plurality of conductive vias without being surrounded by annular metal rings. The conductive vias are conducted with the conductive pads of the first circuit layer and the second circuit layer. Besides, the surface of the second circuit layer is in the same height as the surface of the dielectric layer. Also, the present invention provides a method for manufacturing the above-mentioned circuit board structure. Therefore, a circuit board having fine circuits can be formed, and the shape of the circuit can be ensured efficiently. Moreover, electric performances of the circuit board can be improved.

Abstract: A method of forming an electrical structure that includes a complex power-signal (CPS) substructure. The CPS substructure is formed and tested to determine whether the CPS substructure satisfies electrical performance acceptance requirements. The testing includes testing for electrical shorts, electrical opens, erroneous impedances, and electrical signal delay. If the CPS substructure passes the testes, then a dielectric-metallic (DM) laminate is formed on an external surface of the CPS substructure. The DM laminate includes an alternating sequence of an equal number N of dielectric layers and metallic layers such that a first dielectric layer of the N dielectric layers is formed on an external surface of the CPS substructure. N is at least 2. A multilevel conductive via is formed through the DM laminate and is electrically coupled to a metal layer of the CPS substructure.

Abstract: An IC package includes: a multi-layered PCB having a plurality of insulating layers and a plurality of conductive pattern layers stacked in sequence and a plurality of via-holes formed through the plurality of the insulating layers for an electrical connection between the layers; and an IC chip disposed in a core insulating layer of the plurality of the insulating layers to be embedded in the multi-layered PCB and including a plurality of input/output pads on their surface. The input/output pads disposed at an outermost area of the IC chip are coupled to outer terminals by connection members without passing through said via-hole, the remaining input/output pads except for the input/output pads disposed at the outermost area of the IC chip are coupled to the outer terminals through the via-hole.

Abstract: A wiring substrate is provided with an insulating resin film; and first and second conductive films provided on the back side and top side of the insulating resin film, respectively. The wiring substrate includes a via formed to fill a recess provided in the insulating resin film and electrically connecting the top side and back side of the insulating resin film. The via includes a first metal film formed to cover the side wall of the recess, an oxide film formed to cover the first meal film, and a second metal film formed on the metal oxide film.

Abstract: An information handling system, e.g., a mainframe computer, which includes as part thereof a housing having therein an electrical assembly including a circuitized substrate which in turn includes a plurality of contiguous open segments which define facing edge portions within an electrically conductive layer to isolate separate portions of the conductive layer such that the layer can be used for different functions, e.g., as both power and ground elements, within the system. At least one electrical component is positioned on and electrically coupled to the circuitized substrate of the system's electrical assembly.

Abstract: A circuit board and a method for fabricating the same are provided. The circuit board includes a core board, a first bonding layer disposed on the core board, and a first wiring layer disposed on the first bonding layer. The first bonding layer enables the first wiring layer to be bonded to the core layer better, thereby preventing delamination and forming a fine-pitch wiring layer.

Abstract: A component built-in module of the present invention includes: a first wiring pattern; an electronic component mounted on the first wiring pattern; a second wiring pattern; an electrical insulating sheet with the electrical component built therein, the electrical insulating sheet being disposed between the first wiring pattern and the second wiring pattern; and a via conductor formed in a via hole penetrating through the electrical insulating sheet, the via conductor connecting electrically the first wiring pattern and the second wiring pattern. A side face of the via conductor defines a continuous line in an axis direction of the via conductor. Thus, a component built-in module having excellent reliability concerning electrical connection can be provided.

Abstract: A wiring board and method of forming a wiring board. The wiring board includes a first substrate and a second substrate having a smaller mounting area than a mounting area of the first substrate. A base substrate is laminated between the first substrate and the second substrate such that the first substrate extends beyond at least one edge of the second substrate. At least one of the base substrate, the first substrate or the second substrate comprises pliable resin, and at least one other of the base substrate, the first substrate or the second substrate comprises an inorganic filler.

Abstract: A wiring unit includes a first insulating layer which is provided with an electrode and a wire electrically connected to the electrode on one surface of the first insulating layer; a second insulating layer which is formed on the one surface of the first insulating layer and which covers the wire; an adhesive layer which is formed on a surface, of the second insulating layer, not facing the first insulating layer; a through hole which is formed through the adhesive layer and the second insulating layer and in which the electrode is exposed; a protective sheet which is detachably adhered on a surface, of the adhesive layer, not facing the second insulating layer, and; and a liquid electroconductive material which is filled in a space defined by the through hole, the electrode exposed in the through hole, and the protective sheet.

Abstract: A multilayer interconnection board includes a plurality of stacked insulation layers, wiring layers in the insulation layers, and via forming parts for interlayer connection, the via forming parts piercing the insulation layers. In the multilayer interconnection board, 0<L2?(L1/3) is set, where L1 denotes the distance between center positions of a pair of neighboring via forming parts formed in the same insulation layer and L2 denotes the shortest separation distance between the pair of the via forming parts.

Abstract: A fabricating process for an embedded circuit structure is provided. A through hole is formed in a core panel and penetrates the core panel. Two indent patterns are respectively formed on two opposite surfaces of the core panel. A conductive material is electroplated into the through hole and the indent patterns, so as to form a conductive channel in the through hole and two circuit patterns in the indent patterns respectively. Portions of the circuit patterns, which exceed the indent patterns respectively, are removed for planarizing the circuit patterns to be level with the two surfaces of the core panel respectively.

Abstract: Provided is a method of manufacturing a printed circuit board. In an embodiment, the method includes forming a prepreg layer via a reel method, forming a conductive film for forming a circuit pattern on at least one surface of the prepreg layer; and forming a predetermined circuit pattern on the conductive film. In an embodiment, the prepreg layer has a thickness of at most about 0.15 mm and contains a fiber material and a resin material. In an embodiment, the content of the resin material in the prepreg layer is about 70% or less by volume. In an embodiment, the prepreg layer is composed of at least one prepreg layer.

Abstract: A multi-conducting through hole structure is provided. The multi-conducting through hole structure has a substrate, at least two signal lines and at least a reference line. The substrate has a through hole passing therethrough. The signal lines are disposed on a portion of an inner surface of the through hole and extended through the through hole. The reference line is disposed on a portion of the inner surface of the through hole and extended through the through hole, wherein the reference line is disposed between the lines for signal. Because the signal lines are separated by the reference line, the electromagnetic coupling generated by signals can be reduced to lower the cross-talk interference between signals passing through the through hole, so as to promote the signal-transmission quality.

Abstract: An electromagnetic bandgap structure and a printed circuit board that can solve a mixed signal problem between an analog circuit and a digital circuit are disclosed. In accordance with an embodiment of the present invention, an electromagnetic bandgap structure is stacked with a first metal layer, a first dielectric layer, a metal plate, a second dielectric layer and a second metal layer, and an odd number of vias can be serially connected through a metal line between the first metal layer and the metal plate. This electromagnetic bandgap structure can have a small size and a low bandgap frequency.

Abstract: A printed circuit board, which increases the contact area between an IC and a printed circuit board, thus increasing the degree of adhesion, is disclosed. The printed circuit board includes: an insulation layer which includes a first circuit pattern, including at least one via land, embedded in the upper surface of the insulation layer to be flush with the upper surface, and a second circuit pattern formed in the lower surface of the insulation layer to be flush with the lower surface; a solder resist layer formed on the insulation layer; a via hole and a bump integrally formed on the second circuit pattern through the via hole and the via land such that it protrudes from the insulation layer to be higher than the solder resist layer.

Abstract: A parallel chip embedded printed circuit board and manufacturing method thereof are disclosed. With a method of manufacturing a parallel chip embedded printed circuit board, comprising: (a) forming a parallel chip by connecting in parallel a plurality of unit chips having electrodes or electrically connected members formed on the upper and lower surfaces thereof, using at least one conductive member; (b) joining an electrode on one side of the parallel chip to a first board; and (c) joining an electrode on the other side of the parallel chip to a second board, chips may be embedded in a printed circuit board at a low cost, as a plurality of unit chips can be embedded at once, and a mechanical drill or router can be used instead of a laser drill in perforating the cavity or via holes.

Abstract: A printed circuit board solving a mixed signal problem between an analog circuit and a digital circuit is disclosed. In accordance with an embodiment of the present invention, the printed circuit board, having an analog circuit and a digital circuit, includes: a first metal layer and a second metal layer, one of the first metal layer and the second metal layer being a power layer and the other being a ground layer; a third metal layer, layer-built between the first metal layer and the second metal layer; and a mushroom type structure including a via connected to a metal plate, the metal plate being arranged-in a space between circuit patterns of the third metal layer. With the present invention, the printed circuit board can lower the noise level within the same frequency band as compared with other structures having the same size.

Abstract: A land grid array (LGA) interposer structure, including an electrically insulating carrier plane, and at least one interposer mounted on a first surface of said carrier plane. The interposer possesses a hemi-toroidal configuration in transverse cross-section and is constituted of a dielectric elastomeric material. A plurality of electrically-conductive elements are arranged about the surface of the at least one hemi-toroidal interposer and extend radically inwardly and downwardly from an uppermost end thereof into electrical contact with at least one component located on an opposite side of the electrically insulating carrier plane. Provided is also a method of producing the land grid array interposer structure.

Abstract: This invention relates to a multilayer printed circuit board and a method of fabricating the same, which can increase the reliability of the multilayer printed circuit board and can decrease the process time to thus improve productivity.

Abstract: Systems and methods for simultaneously partitioning a plurality of via structures into electrically isolated portions by using plating resist within a PCB stackup are disclosed. Such via structures are made by selectively depositing plating resist in one or more locations in a sub-composite structure. A plurality of sub-composite structures with plating resist deposited in varying locations are laminated to form a PCB stackup of a desired PCB design. Through-holes are drilled through the PCB stackup through conductive layers, dielectric layers and through the plating resist. Thus, the PCB panel has multiple through-holes that can then be plated simultaneously by placing the PCB panel into a seed bath, followed by immersion in an electroless copper bath. Such partitioned vias increase wiring density and limit stub formation in via structures. Such partitioned vias allow a plurality of electrical signals to traverse each electrically isolated portion without interference from each other.

Abstract: A sequentially laminated printed circuit board having highly reliable vias can be fabricated by pattern plating flanges or via lands on a copper foil, laminating the foil to a prepreg so that the flanges are embedded into the surface of the prepreg, creating via holes in the laminate that are substantially concentric with the individual flanges, plating the via holes with copper, chemically or mechanically milling off a portion of the copper plating and optionally some of the copper foil to reduce the overall thickness of the laminate, and laminating a second and optionally a third prepreg to the laminate. The resulting printed circuit board has the flanges embedded in the surface of the laminate so that the inside wall of the flange is electrically and mechanically attached to the outside wall of the plated through hole barrel.

Abstract: A printed circuit board using paste bumps and manufacturing method thereof are disclosed.

Abstract: A wiring board and 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) or through hole penetrates the base substrate and vias are formed in at least one of the first substrate or the second substrate.

Abstract: In a method of manufacturing a wiring substrate of the present invention, a through-hole plating layer is formed from an inner surface of a through hole in a substrate to both surface sides, then a resin is filled in a through hole, and then a first resist in which an opening portion is provided on the through hole is formed. Then, a partial cover plating layer is formed in the opening portion in the first resist, then the first resist is removed, and then a second resist that covers a whole of the partial cover plating layer and has a pattern for patterning the through-hole plating layer is formed. Then, a pad wiring portion containing the partial cover plating layer and a wiring pattern are obtained by etching the through-hole plating layer while using the second resist as a mask.

Abstract: A printed circuit board and a method of manufacturing a printed circuit board are disclosed. Using a method of manufacturing a printed circuit board, which includes: forming a multilayer board by alternately stacking circuit pattern layers and insulation layers such that a predetermined thickness of a partial area has only insulation layers stacked therein; and removing insulation layers from the partial area of the multilayer board, a printed circuit board can be manufactured that is suitable for a slim module.

Abstract: A semiconductor device 100 has such a structure that a semiconductor chip 110 is flip-chip mounted on a wiring board 120. The wiring board 120 has a multilayer structure in which a plurality of wiring layers and a plurality of insulating layers are arranged, and a first electrode pad 130 is formed on a chip mounting side. A taper surface 132 of the first electrode pad 130 has a gradient in an orientation reduced in an upward direction toward a solder connecting side or a chip mounting side. Therefore, a holding force for a force applied to the solder connecting side or the chip mounting side is increased, and furthermore, the taper surface 132 adheres to a tapered internal wall of an insulating layer of a first layer so that a bonding strength to the insulating layer is increased.

Abstract: A solvent-free filling material comprising a filler, a thermosetting resin, a curing agent, and a curing catalyst, wherein the thermosetting resin is an epoxy resin, and the curing agent is a dicyandiamide curing agent; a multilayer printed wiring board comprising a substrate, a through-hole, the filling material filling the through-hole, and a conductor layer formed on an exposed surface of the filling material in the through-hole; and a process for producing the multilayer printed wiring board.

Abstract: A method for manufacturing a multilayer FPCB includes the steps of: providing a first substrate, a second substrate and a binder layer; defining an opening on the binder layer; defining a first slit in the dielectric layer of the first substrate; laminating the first substrate, the binder layer and the second substrate; forming a second slit in the conductive layer of the first substrate, the second slit is configured to be aligned with the first slit, cutting the first substrate, the binder layer and the second substrate thereby forming a multilayer flexible printed circuit board having different numbers of layers in different areas.

Abstract: A circuit board is manufactured by filling a via-hole formed in an insulating substrate with conductive material, disposing conductive layers on both sides of the insulating substrate, and forming alloy of component material of the conductive material with component material of the conductive layers. In the circuit board, therefore, the conductive material filled in the via-hole formed in the insulating substrate is securely connected electrically as well as mechanically to the conductive layers on both sides of the insulating substrate with high reliability.

Abstract: A wiring substrate, in which a wiring stacked portion including a conductor layer and a resin layer is stacked on a principal face of a core substrate including a substantially cylindrical through hole conductor in a through hole extending therethrough and a filling material filling a hollow portion of said through hole, comprising: a cover-shaped conductor portion covering an end face of said through hole just above a principal face of said core substrate and connected to said through hole conductor; and a terminal pad conductor provided over a principal face of said wiring stacked portion for disposing connection terminals used for connections with an external device, wherein a connection portion composed of via conductors buried in said resin layer brings said cover-shaped connection portion and said terminal pad conductor into conduction, and said via conductors composing said connection portion are provided not above a center axis of said through hole.

Abstract: A circuit board and a circuit apparatus using the same are provided, which have an improved heat radiation capability near through holes piercing through its metal substrate so as to address a requirement as to heat radiation capability. The circuit apparatus has the circuit board in which a metal substrate having pierced holes is formed as a core member. Protrusions are formed at the top ends of the pierced holes, and round corners are formed at the bottom ends of the same. Insulating layers are formed on both sides of the metal substrate, and wiring pattern layers are formed on the respective insulating layers. The insulator formed on one side of the metal substrate and the insulator formed on the other side of the metal substrate are extended to inside the pierced holes. The joining surface between the extended portions is shifted off the center position of the metal substrate in the thickness direction, toward the same side as where the protrusions are formed.

Abstract: A printed circuit board manufacturing method includes: a hole-forming step of forming a through hole in a substrate that will become an element of a printed circuit board after manufacturing; and a jig insertion step of inserting a jig in the through hole formed in the hole-forming step such that the jig adheres to a portion of an inner wall of the through hole, the inner wall having a portion connecting to the outside of the through hole. The method further includes a conductive-film forming step of forming a conductive film only on the portion of the inner wall of the through hole connecting to the outside of the through hole, after the jig is inserted into the through hole in the jig insertion step.

Abstract: Trace configurations for carrying high-speed digital differential signals provide for reduced conduction loss and improved signal integrity. In one embodiment, a circuit board has a first set of conductive traces disposed on non-conductive material, and a second set of conductive traces parallel to the first set and disposed within the conductive material. The second set is separated from the first set by non-conductive material. Corresponding traces of the first and second sets may be in a stacked configuration. In other embodiments, conductive material may be provided between corresponding traces of the first and second sets resulting in an “I-shaped” or “U-shaped” cross-section. In yet other embodiments, the trace configurations have “T-shaped” and “L-shaped” cross-sections.

Abstract: Printed circuit boards have circuit layers with one or more copper filled through-holes and methods of manufacturing the same. An aspect of an embodiment of the present invention enhances thermal characteristics of filled through-holes of printed circuit boards to provide extra reliability to the printed circuit boards. In one embodiment, a printed circuit broad has a plurality of through-holes to connect copper patterns on different layers of the printed circuits broad. Here, at least one of the through-holes is copper plated closed at both ends with at least 70% volume of the through-hole plated with copper to, e.g., enhance thermal characteristics of the through-hole, thereby providing extra reliability to the printed circuit board. In one embodiment, the printed circuit board includes a surface conductor (or cap) that is directly plated over the copper filled barrel plated through-hole.

Abstract: An object of the present invention is to provide a multilayered printed circuit board having a short wiring distance of the conductor circuits, wide option of the design of the conductor circuits and additionally excellent in reliability since cracking scarcely takes place in the interlaminar resin insulating layers in the vicinity of via-holes. The present invention is a multilayered printed circuit board comprising: a conductor circuit and an interlaminar resin insulating layer serially formed on a substrate in alternate fashion and in repetition, wherein a connection of the conductor circuits through the interlaminar resin insulating layers is performed by a via-hole, wherein via-holes in different level layers among the via-holes are formed so as to form a stack-via structure, and wherein at least one of the land diameters of the above-mentioned via-holes in different level layers having the stack via structure is different from the land diameters of other via-holes.

Abstract: A multi-layer electronic device can be formed to include an insulative substrate (212), a first vapor deposited conductor layer (312) on the insulative substrate (212), a first vapor deposited insulator layer (314) on the first conductor layer (312), the first insulator layer (314) having at least one via hole (316) therein, and a vapor deposited conductive filler (320) in the via hole (316) of the first insulator layer (314). Desirably, the conductive filler (320) is deposited in the via hole (316) of the first insulator layer (314) such that the surface of the conductive filler (320) opposite the first conductor layer (312) is substantially planar with the surface of the first insulator layer (314) opposite the first conductor layer (312).

Abstract: A circuit board of the present invention, includes: an electrical insulating layer including at least one layer of electrical insulating base; and a conductive portion formed in a via hole provided in the electrical insulating base. A land for mounting only is disposed on at least one surface of the electrical insulating base that is arranged at an outermost layer. According to a method for manufacturing a circuit board of the present invention, includes the steps of: forming a via hole in an electrical insulating base; filling the via hole with a conductive paste; laminating a metal foil or a releasing sheet on the electrical insulating base, and placing a jig for pressing above and below the lamination, followed by hot-pressing so as to apply heat and pressure thereto, so as to form a conductive portion made of the conductive paste in the via hole; and forming a land for mounting only on at least one surface of the electrical insulating base that is arranged at an outermost layer.

Abstract: Disclosed is a PCB having axially parallel via holes, in which an outer ground via hole, acting as a ground, is formed around a via hole for intercircuit connection in the PCB, thereby minimizing the effect of noise caused by the via hole.

Abstract: An electronic component mounting structure includes a board and an electronic component mounted on a surface of the board. The board includes lands. The electronic component includes a body and terminals extending from the body. Each terminal is electrically connected to a corresponding one of the lands of the board. The terminal has a first terminal portion extending along the surface of the board and a second terminal portion extending toward the surface of the board. Each land includes a land portion electrically soldered to the first terminal portion and a blind hole for receiving the second terminal portion. The first terminal portion is soldered to the land portion in a reflow process under the condition that the second terminal portion is inserted in the blind hole.

Abstract: A ceramic electronic component achieves a sufficient drop resistance strength even when terminal electrodes are formed with a higher density. The ceramic electronic component includes a ceramic laminate including ceramic laminates which are laminated to each other, first terminal electrodes disposed in a peripheral portion of a bottom surface of the ceramic laminate, catch pad electrodes arranged in the ceramic laminate so as to face the respective first terminal electrodes, and sets each including at least two first via hole conductors, which electrically connect the first terminal electrodes and the respective catch pad electrodes.

Abstract: A wiring substrate has pads formed from a plurality of metal layers and vias connected to the pads. The plurality of metal layers have a metal layer exposed through the wiring substrate, and a first metal layer which is interposed between the metal layer and the vias and which prevents diffusion of metal included in the vias into the metal layer. A second metal layer which is less subject to oxidation than the first metal layer is provided between the vias and the first metal layer, and the vias are connected to the second metal layer.

Abstract: An intermediate layer 38 is provided on a die pad 22 of an IC chip 20 and integrated into a multilayer printed circuit board 10. Due to this, it is possible to electrically connect the IC chip 20 to the multilayer printed circuit board 10 without using lead members and a sealing resin. Also, by providing the intermediate layer 38 made of copper on an aluminum pad 24, it is possible to prevent a resin residue on the pad 24 and to improve connection characteristics between the die pad 24 and a via hole 60 and reliability.

Abstract: The present invention provides a multilayer printed wiring board having a filled viahole structure advantageously usable for forming a fine circuit pattern thereon, and having an excellent resistance against cracking under a thermal shock or due to heat cycle. The multilayer printed wiring board is comprised of conductor circuitry layers and interlaminar insulative resin layers deposited alternately one on another, the interlaminar insulative resin layers each having formed through them holes each filled with a plating layer to form a viahole. The surface of the plating layer exposed out of the hole for the viahole is formed substantially flat and lies at a substantially same level as the surface of the conductor circuit disposed in the interlaminar insulative resin layer. The thickness of the conductor circuitry layer is less than a half of the viahole diameter and less than 25 ?m.

Abstract: A high speed interposer which includes a substrate having alternatingly oriented dielectric and conductive layers which form a substrate, openings which extend from one opposing surface of the substrate to a second opposing surface, conductive members positioned within the openings and also extending from surface to surface (and beyond, in some embodiments), and a plurality of shielding members positioned substantially around the conductive members to provide shielding therefore during the passage of high frequency signals through the conductive members.

Abstract: The present invention relates to a method of manufacturing a wiring board comprising: a build-up layer, in which wiring patterns are piled with insulating layers; and a core substrate, which is separately formed from the build-up layer, the method comprising the steps of: separably forming the build-up layer on a plate-shaped support; electrically connecting the core substrate to the wiring patterns of the build-up layer on the support; and removing the support from the build-up layer so as to form the wiring board, in which the build-up layer is connected to the core substrate. By separably forming the build-up layer and the core substrate, the wiring board effectively exhibiting characteristics thereof can be produced.

Abstract: Signal line conductors passing through vertical vias in an insulative substrate for supporting and interconnecting integrated circuit chips are provided with shielding conductors in adjacent vias that link respective power and ground planes. The shielding conductors' presence in positions around a signal via is made possible through the employment of power plane and ground plane conductive grids that are laid out in rhomboid patterns. The power plane and ground plane grids possess a left-right mirror relation to one another and are displaced to place the rhomboid's corners to avoid overlapping any of the grid lines.

Abstract: A wired circuit board having improved adhesion between the conductive pattern and an insulating layer to prevent a plating solution from remaining between a metal plating layer and the insulating layer. The invention prevents ionic impurities in the plating solution from remaining as residual or ionic contamination, thereby preventing a short circuit from developing when electric current flows through the circuit under a high temperature and high humidity environment. Lower end portions of the terminal portions that are formed on an insulating base layer and lower end portions of side surfaces and metal plating layers that cover the terminal portions are embedded in the insulating base layer in a flexible wired circuit board.

Abstract: A signal transmission structure is provided. The structure mainly comprises at least a conductive via, at least a via land and a conductive wall. One end of the conductive via is connected to the via land. The conductive wall covers only a portion of the inner wall of a through hole in the core layer of a circuit substrate. The conductive wall has a semi-circular or a C-shaped structure. Therefore, when a signal passes the conductive via and the via land of the circuit substrate through the conductive wall in the interior of the via, because of a more continuous impedance between the via land and the conductive wall, signal reflection due to impedance mismatch along the signal transmission pathway can be reduced to enhance signal transmission quality.

Abstract: A printed wiring board for mounting electronic components includes an insulating layer and a wiring pattern formed on one surface of the insulating layer, wherein one end portion of a filled via 4 is connected with the wiring pattern and the other end portion is overlaid with a covering layer 9 obtained by applying a conductive paste to cover at least the boundary between the filled via 4 and the insulating layer 2; alternatively, a plating resist 7 is formed at the other end portion to cover at least the boundary between the filled via 4 and the insulating layer 2, and is removed after an end portion of the filled via 4 enclosed within the plating resist 7 is plated to produce a terminal layer, thereby preventing a wet processing liquid such as a tin plating solution from leaking in between the filled via 4 and the insulating layer 2.