A wiring substrate includes an insulating layer including inorganic filler particles and resin, and a conductor layer including a metal film formed on a surface of the insulating layer and having a conductor pattern. The inorganic filler particles include first inorganic filler particles such that each of the first inorganic filler particles has a portion exposed on the surface of the insulating layer and is at least partially separated from the resin, the conductor layer is formed such that a part of the metal film is between the first inorganic filler particles and the resin from the surface of the insulating layer and that a distance between the surface of the insulating layer and the surface of the insulating layer at a deepest part of the part of the metal film is in the range of 0.1 μm to 0.5 μm.

A wiring substrate includes a first conductor pattern, a second conductor pattern, an insulating layer interposed between the first and second patterns and having a through hole, and a plating conductor integrally formed with the second pattern and filling the through hole in the insulating layer such that the plating conductor is in contact with the first pattern. The through hole has an expansion part such that an opening width of the through hole on the first pattern side is widened, and the plating conductor includes a first plating film directly formed on inner wall of the through hole and a second plating film formed on the first plating film such that the minimum thickness of the first plating film in the expansion part is in the range of 55% to 95% of the minimum thickness of the first plating film in the through hole other than the expansion part.

A dielectric tape suitable for use in an electronic device is provided. A dielectric slip composition comprises an organic vehicle and a dielectric glass composition comprising at least about 20 wt % and no more than about 50 wt % silicon dioxide, based upon 100% total weight of the glass composition, at least about 10 wt % and no more than about 50 wt % alkali metal oxides, based upon 100% total weight of the glass composition, and at least about 1 wt % and no more than about 10 wt % of at least one transition metal oxide. A method of forming an electronic device is also provided. The method includes the steps of applying at least one dielectric tape to at least one non-planar surface of a substrate, and subjecting the at least one dielectric tape to one or more thermal treatment steps to form a dielectric layer.

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.

A high-CTI and halogen-free epoxy resin composition for copper-clad plates and uses thereof is provided. The formula of the high-CTI and halogen-free epoxy resin composition for copper-clad plates comprises 100˜140 parts of halogen-free phosphorous epoxy resin, 10˜35 parts of dicyclopentadiene phenolic epoxy resin, 32˜60 parts of benzoxazine, 1˜5 parts of phenolic resin, 0.05˜0.5 parts of accelerants; and 25˜70 parts of fillers, by weight. The copper-clad plates, prepared according to embodiments of the present invention, can reach the requirements of high CTI (CTI≧500V), high heat resistance(Tg≧150 ° C., PCT, 2 h>6 min) and the level of flame retardance of UL-94 V0, and they are widely used in the electronic materials of electric machines, electric appliances, white goods and so on.

The present disclosure generally relates to stacked miniaturized electronic devices and methods of forming the same. More specifically, embodiments described herein relate to semiconductor device spacers and methods of forming the same. The semiconductor device spacers described herein may be utilized to form stacked semiconductor package assemblies, stacked PCB assemblies, and the like.

A method of manufacturing a hexagonal boron nitride laminate contains steps of: a) Dissolve dielectric polymers in solvent. b) Mixing h-BN powder to form a well-mixed h-BN coating slurry. c) Coating slurry on substrates and dried at 100-150° C. The substrates can directly be etched or processed to form electric circuits. Substrates can also be completely etched or detached to attain a free standing laminate. Thereby, a hexagonal boron nitride laminate exhibit thermal conductivity of 10 to 40 W/m.Math.K, which is significantly larger than that currently used in thermal management. In addition, thermal conductivity of hexagonal boron nitride laminates increases with the increasing mass density, which opens a way of fine tuning of its thermal properties. For heat dissipation application, hexagonal boron nitride laminate coating can significantly enhance the performance of LED light bulb.

To provide a curable resin composition, from which a cured product having high heat resistance, a low dielectric loss tangent, high adhesion to a conductor can be obtained. A dry film, a resin-clad copper foil, a cured product, and an electronic component containing the curable resin composition are to be provided. A curable resin composition containing (A) an epoxy resin and (B) a compound having an active ester group is obtained, which has ratio of the total amount of epoxy group(s) in (A) the epoxy resin/the total amount of active ester group(s) in (B) the compound having an active ester group in the composition in the range of 0.2 to 0.6. A dry film, a resin-clad copper foil, a cured product, and an electronic component containing the curable resin composition are also obtained.

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 substrate includes an insulating layer including inorganic fillers and resin, and a conductor layer formed on a surface of the insulating layer and having a conductor pattern. The surface of the insulating layer has an arithmetic average roughness Ra in the range of 0.05 μm to 0.5 μm, the conductor layer includes a metal film formed on the surface of the insulating layer, and the inorganic fillers include a first inorganic filler including particles such that each of the particles has a portion of a surface separated from the resin and forming a gap with respect to the resin of the insulating layer and that the metal film of the conductor layer includes part formed in the gap between the first inorganic filler and the resin.