An embedded printed circuit board includes a first substrate, a semiconductor chip mounted on the first substrate, a second substrate provided on the first substrate via the semiconductor chip so that the semiconductor chip is sandwiched between the first substrate and the second substrate, a first resin filled between the semiconductor chip and the first substrate and having a cladding portion covering a side surface of the semiconductor chip, and a second resin filled between the first substrate and the second substrate and encapsulating the semiconductor chip and the first resin. The first resin includes a protrusion protruding from the cladding portion toward the second substrate.

Disclosed is a circuit material, including dielectric substrate or a circuit subassembly further comprising a conductive layer, that is formed from a precursor composition, wherein the precursor composition comprises, based on the total weight of the precursor composition, thermosetting resin or thermoplastic polymer, optionally monomeric triallyl isocyanurate or triallyl cyanurate, dispersed particles of poly(triallyl isocyanurate) or poly(triallyl cyanurate), and optionally inorganic filler, wherein the circuit material has a D.sub.f of less than 0.0060 at 10 GHz. Also disclosed is a method of manufacturing such a circuit material in which emulsion polymerized particles of poly(triallyl isocyanurate) or poly(triallyl cyanurate) are dispersed in a thermosetting or thermoplastic resin.

The present invention relates to a halogen-free epoxy resin composition, a prepreg, a laminate and a printed circuit board containing the same. The halogen-free epoxy resin composition comprises an epoxy resin and a curing agent. Taking the total equivalent amount of the epoxy groups in the epoxy resin as 1, the active groups in the curing agent which react with the epoxy groups have an equivalent amount of 0.5-0.95. By controlling the equivalent ratio of the epoxy groups in the epoxy resin to the active groups in the curing agent to be 0.5-0.95, the present invention ensures the Df value stability of prepregs under different curing temperature conditions while maintaining a low dielectric constant and a low dielectric loss. The prepregs and laminates prepared from the resin composition have comprehensive performances, such as low dielectric constant, low dielectric loss, excellent flame retardancy, heat resistance, cohesiveness, low water absorption and moisture resistance, and are suitable for use in halogen-free multilayer circuit boards.

Through hole filling pastes which include a magnetic powder (A), an epoxy resin (B), and a curing agent (C), in which the magnetic powder (A) is surface-treated with a surface treating agent containing at least one element selected from Si, Al, and Ti, are capable of achieving a cured product excellent in plating adhesion.

Resin sheets which includes a support and a resin composition layer in contact on the support, and which are characterized in that an extracted water conductivity A of a cured product of the resin composition layer when extracted at 120° C. for 20 hours is 50 μS/cm or less and an extracted water conductivity B of the cured product of the resin composition layer when extracted at 160° C. for 20 hours is 200 μS/cm or less, can provide a thin insulating layer having excellent insulating properties.

A wiring board includes a core layer having a first through hole formed therein, a magnetic resin filled inside the first through hole, a second through hole formed in the magnetic resin, and a plating film covering an inner wall surface of the second through hole. The plating film includes an electroless plating film, and an electrolytic plating film. The electroless plating film makes direct contact with an inner wall surface of the second through hole.

A physical quantity detector includes a housing, a circuit board, a cover, a resin member, a conductor, and a conductive member. The circuit board includes a board surface. The cover faces the board surface and defines, together with the hosing, a passage through which the target fluid flows. The conductor includes a passage side portion and a connecting portion. The conductive member electrically connects the connecting portion to the circuit board. The conductive member includes a first end in the thickness direction facing a contact target that is either one of the connecting portion or the board surface. The first end includes a contact portion in contact with the contact target and a contactless portion away from the contact target in the thickness direction.

A laminated uncured sheet of the present disclosure has a structure in which resin sheet layers and resin layers are alternately laminated and a through hole penetrating in the laminating direction is formed, wherein the resin sheet layers are formed with a thermosetting resin composition containing a thermosetting resin as a main component, the resin layers are formed with a thermoplastic resin composition containing a thermoplastic resin, and the thermoplastic resin composition is adhered to the inner wall surface of the resin sheet layer part in the through hole.

Provided are a circuit board, an apparatus and a method for forming a via hole structure. A via hole structure formed on a main body (10) of a circuit board includes a hole (12) enclosed by a conductive layer in the main body (10), the conductive layer constitutes a wall (11) of the hole (12), and a dielectric filling layer (13), which has a dielectric constant smaller than that of the main body (10), is disposed between at least a portion of the wall (11) of the hole (12) and the main body (10), so that the parasitic capacitance of a via hole is decreased, and the impedance of the via hole is increased to become closer to the impedance of a transmission line, thereby effectively improving impedance continuity of a system link.

Provided are a circuit board, an apparatus and a method for forming a via hole structure. A via hole structure formed on a main body (10) of a circuit board includes a hole (12) enclosed by a conductive layer in the main body (10), the conductive layer constitutes a wall (11) of the hole (12), and a dielectric filling layer (13), which has a dielectric constant smaller than that of the main body (10), is disposed between at least a portion of the wall (11) of the hole (12) and the main body (10), so that the parasitic capacitance of a via hole is decreased, and the impedance of the via hole is increased to become closer to the impedance of a transmission line, thereby effectively improving impedance continuity of a system link.