Abstract:
The present invention provides an at least partially coated fiber strand comprising a plurality of glass fibers having a resin compatible coating composition on at least a portion of a surface of at least one of said glass fibers, the resin compatible coating composition comprising: (a) a plurality of lamellar, inorganic particles and (b) at least one polymeric material. The present invention further provides that the resin compatible coating composition comprises (a) a plurality of discrete particles formed from materials selected from non-heat expandable organic materials, inorganic polymeric materials, non-heat expandable composite materials and mixtures thereof, the particles having an average particle size sufficient to allow strand wet out; (b) at least one lubricious material different from said plurality of discrete particles; and (c) at least one film-forming material. The present invention further provides that the resin compatible coating composition comprises (a) a plurality of hollow, non-heat expandable organicparticles; and (b) at least one lubricious material different from the at least one hollow organic particle.
Abstract:
A flexible circuit includes a flexible non-conductive substrate (12) having a first surface and a second surface. A first electrically conductive trace (18) is provided on the first surface and a second electrically conductive trace (20) is provided on the second surface. A passage (22) extends through the substrate from an end of the first trace to an end of the second trace. The passage includes a beveled opening (26) of a first size formed in the first side and axially aligned with a second beveled opening (28) of the first size formed in the second side. The first and second openings are interconnected by an aperture axially aligned therewith and being of a second size less than the first size. An electrically conductive surface is provided on the passage for electrically interconnecting the first trace and the second trace.
Abstract:
The present invention relates to a method of producing a laminate base material useful for preparing a prepreg or a laminate for electronic equipment such as printed board. The method comprises the steps of:
(1) preparing a slurry comprising para-aramid fibers and curable phenolic resin fibers; (2) preparing a sheet from said slurry; (3) adding a resin binder to said sheet so as to bond the fibers with each other, thereby to form a combined non-woven fabric and (4) compressing said non-woven fabric under heating.
According to the present invention, a prepreg or laminate is obtained which has an improved high-frequency characteristics and much less warp.
Abstract:
Provided is a composite film comprising a continuous phase of para-oriented aromatic polyamide and a phase of low-dielectric resin, said film having a dielectric constant at 1 MHz of not more than 3.2 and a linear thermal expansion coefficient at 200 to 300°C of within ±50×10 -6 /°C. The composite film has characteristics such as a low dielectric constant, favorable mechanical strength, homogeneous structure, light weight, and a low linear thermal expansion coefficient, and the film is useful as a base substrate for a flexible printed circuit board.
Abstract:
A differentiable ablation approach to patterning dielectrics which are not of the same absorbance uses an absorbant dielectric (20) at a specified laser wavelength over a non-absorbant dielectric (18) at that wavelength. The absorbant dielectric may be laser-patterned and become an integral mask enabling plasma etching of the underlying non-absorbant dielectric. If the patterning of the absorbant dielectric involves vias, polymer ridges formed around via surfaces during laser patterning may be removed at the same time the underlying non-absorbant dielectric is etched using a transparent, oxygen plasma resistant mask. Alternatively, an inert mask may be used instead of the absorbent dielectric to allow plasma etching of the non-absorbant dielectric.
Abstract:
A circuit board comprising: a core material consisting of any one selected from the group consisting of magnesium, a magnesium alloy, and a magnesium-based composite material; and an electric circuit formed on the core material. A process for producing the circuit board comprises: forming an electrodeposition-painted coating on such a core material; forming a polyimide resin coating on the electrodeposition-painted coating; forming a viahole extending through the resin coating to the underlying electrodeposition-painted coating; etching and removing the electrodeposition-painted coating in the region exposed in the bottom of the viahole while masking the other region with the resin coating, to extend the viahole to the core material; forming a metal film at least on a free surface of the resin coating and a inner surface of the extended viahole; and etching the metal film by using a photoresist mask to form a conductor layer having a predetermined pattern.
Abstract:
A two-layer film carrier for TAB is made from a substrate (1) prepared by forming a copper layer (2) on a polyimide film by additive plating. A photoresist layer (3) is formed on the copper layer, and another photoresist layer (3) on the polyimide film. Both of the photoresist layers are simultaneously exposed to light through a mask applied to each of them to define a desired pattern. The exposed portions of the photoresist layer on the copper layer are subjected to development and postbaking, whereby selected portions of the copper layer are exposed. The exposed portions of the copper layer are additive plated with copper, whereby leads (4) are formed. The exposed portions of the photoresist layer on the polyimide film are subjected to development and postbaking, whereby selected portions of the polyimide film are exposed (5, 6, 7). The remaining portions of the photoresist layer are removed from the copper layer and the underlying copper layer is etched. The exposed portions of the polyimide film are etched, and the remaining portions of the photoresist layer are removed from the polyimide film.
Abstract:
The invention relates to a printed wiring board which forms printed circuit conductors (2) on at least one surface of a base plate (1) and having a solder resist layer (3) on at least a portion of the base plate (1) having the conductors (2). The solder resist film (3) is a foamed material which contains a foamable agent mixed with a main composition of the solder resist film forming ink.