A printed circuit board package structure includes a substrate, plural ring-shaped magnetic elements, a support layer, and first conductive layers. The substrate has two opposite first and second surfaces, first ring-shaped recesses, and first grooves. Each of the first ring-shaped recesses is communicated with another first ring-shaped recess through at least one of the first grooves, and at least two of the first ring-shaped recesses are communicated with a side surface of the substrate through the first grooves to form at least two openings. The ring-shaped magnetic elements are respectively located in the first ring-shaped recesses. The support layer is located on the first surface, and covers the first ring-shaped recesses and the first grooves. The support layer and the substrate have through holes. The first conductive layers are respectively located on surfaces of support layer and substrate facing the through holes.

A wiring board includes a first wiring layer formed on one surface of a core layer, a first insulating layer formed on the one surface of the core layer so as to cover the first wiring layer, a via wiring embedded in the first insulating layer, a second wiring layer formed on a first surface of the first insulating layer, and a second insulating layer thinner than the first insulating layer formed on the first surface of the first insulating layer so as to cover the second wiring layer. The first wiring layer comprises a pad and a plane layer provided around the pad. One end surface of the via wiring is exposed from the first surface of the first insulating layer and directly bonded to the second wiring layer. The other end surface of the via wiring is directly bonded to the pad in the first insulating layer.

The object is to provide a resin composition for a printed circuit board capable of realizing a printed circuit board that not only has heat resistance and flame retardancy but also is excellent in heat resistance after moisture absorption. The resin composition is a resin composition for a printed circuit board containing a cyanate ester compound (A) obtained by cyanation of a naphthol-dihydroxynaphthalene aralkyl resin or a dihydroxynaphthalene aralkyl resin, and an epoxy resin (B).

The present invention provides a process for preparing a pre-treated low Dk-type glass fabric for constituting a circuit board, comprising pre-treating low Dk-type glass fabric with a pre-treating varnish having a Dk close to the Dk of the used low Dk-type glass fabric at different temperatures and having a small Df. The present invention further provides a bonding sheet and a circuit board prepared thereby. The circuit boards prepared by the preparation process of the present invention have a Dk having small differences in warp and weft directions, and can effectively solve the problem of signal propagation delay. The circuit boards have a small Df, so as to have a small signal loss. Meanwhile, the cured, partially-cured or uncured dry glue obtained after drying the solvent of the pre-treating varnish has similar dielectric properties at different temperatures to the used low Dk-type glass fabric, so that the circuit boards have a very small signal propagation delay at different temperatures.

A lamination circuit board structure lamination circuit board structure includes a printed circuit board substrate including conductive wiring traces on at least a first wiring face, a prepreg layer formed over the first wiring face, and a patch having an area smaller than 1,000 mm.sup.2. The patch includes conductive wiring traces formed on a wiring face and is laminated to the printed circuit board substrate over the prepreg layer, oriented with the wiring face in contact with and pressed into the prepreg layer. Portions of the prepreg layer fill interstices between the conductive wiring traces.

The instant invention provides a curable composition suitable for electrical laminate applications, and electrical laminates made therefrom. The curable composition suitable for electrical laminate applications according to the present invention comprises a) an epoxy resin; and b) a hardener compound for curing with the epoxy resin; and c) titanium dioxide.

A resin composition contains an epoxy resin, and a curing agent including a first acid anhydride and a second acid anhydride. An unsaturated bond concentration in the second acid anhydride is not higher than 0.7%. The unsaturated bond concentration is represented by following formula (1). The ratio of the number of acid anhydride equivalents of the first acid anhydride to the number of epoxy equivalents of the epoxy resin is between 0.05 and 0.5 (inclusive). The ratio of the total number of acid anhydride equivalents of the first acid anhydride and the second acid anhydride to the number of epoxy equivalents is between 0.5 and 1.1 (inclusive).

Unsaturated bond concentration={(number of unsaturated bonds per molecule)/(molecular weight)}/(number of acid anhydride groups per molecule)×100  (1)

A curable composition including a radically polymerizable compound containing an unsaturated bond within the molecule, an inorganic filler containing a metal oxide, and a dispersant containing an acidic group and a basic group. The content of the metal oxide is between 80 parts by mass and 100 parts by mass (inclusive) relative to the amount of the inorganic filler of 100 parts by mass. Components of the curable composition other than the inorganic filler are organic components. A content of the inorganic filler is between 80 parts by mass and 400 parts by mass (inclusive) relative to the amount of the organic components of 100 parts by mass. A content of the dispersant is between 0.1 part by mass and 5 parts by mass (inclusive) relative to the amount of the inorganic filler of 100 parts by mass.

A laminate with superior thermal conductivity, heat resistance, drill workability, and fire retardancy is provided. In a prepreg obtained by impregnating a woven or nonwoven fabric base with a thermosetting resin composition, the thermosetting resin composition contains 80 to 200 parts by volume of an inorganic filler per 100 parts by volume of a thermosetting resin, the inorganic filler contains (A) gibbsite type aluminum hydroxide particles having an average particle diameter (D.sub.50) of 2 to 15 μm and (B) magnesium oxide having an average particle diameter (D.sub.50) of 0.5 to 15 μm, and a compounding ratio (volume ratio) of the gibbsite type aluminum hydroxide particles (A) to the magnesium oxide (B) is 1:0.3 to 3.

A molded interconnect device that comprises a substrate and conductive elements disposed on the substrate is provided. The substrate comprising a polymer composition containing a polymer matrix that includes a thermotropic liquid crystalline polymer and from about 10 parts to about 80 parts by weight of a mineral filler per 100 parts by weight of the polymer matrix. The mineral filler has an average diameter of about 25 micrometers or less. The polymer composition contains copper in an amount of about 1,000 parts per million or less and chromium in an amount of about 2,000 parts per million or less, and further exhibits a surface resistivity of about 1×1014 ohm or more.