Abstract:
Provided are a circuit board which meets requirement of suppressing peeling of a through hole conductor, a mounting structure and a method for manufacturing the circuit board. A circuit board (2) is provided with a base (5) and a through hole conductor (11). The base is provided with a fiber layer (9) and a through hole (S). The fiber layer has a single fiber (8) arranged along one direction and a resin for covering the single fiber (8). The through hole (S) penetrates the fiber layer (9), and the through hole conductor is formed in the through hole. The single fiber (8) partially protrudes to the side of the through hole conductor (11) from an inner wall surface of the through hole (S), and the protruded part is covered with the through hole conductor (11).
Abstract:
A semiconductor device has a semiconductor package with a semiconductor element is mounted on a mounting substrate. The mounting substrate has at least two anisotropic areas which are located at both sides of a semiconductor package mounting area in a way to sandwich it and have an anisotropic linear expansion coefficient. In the anisotropic areas, a linear expansion coefficient in a direction toward a center of the semiconductor package mounting area is larger than a linear expansion coefficient in an in-plane direction of the mounting substrate perpendicular to the direction and larger than a linear expansion coefficient of the semiconductor package mounting area in a direction toward the anisotropic areas. The semiconductor device makes it possible to reduce thermal deformation of a semiconductor package mounting area of a mounting substrate easily and at low cost.
Abstract:
Apparatus and methods are presented for reinforcing and stiffening a printed circuit board (PCB) in selected locations by utilizing preferentially oriented fibers. Selected fibers within the polymeric material matrix of the PCB fiber-matrix layer are removed and replaced with a similar quantity of fibers in a preferential orientation. Various combinations of layering of modified fiber-matrix layer material with conventional fiber-matrix layer material are presented to achieve the desired PCB stiffening. Printed circuit boards, under the weight of heavy attached electronic components, may deflect or flex along an axis, defined as the characteristic fold. This flexing is exasperated with manufacturing and handling loading, particularly when mounted in a chassis. Preferentially orientated fibers laid transverse to the characteristic fold reinforces the area to resist flexure within the area surrounding the characteristic fold. Reducing PCB flexure is particularly important in locations of the PCB containing surface mount technology (SMT) components, such as ball grid array electronic components. The lead attachment for BGA components is particularly susceptible to PCB flexure resulting in lead fatigue, fracture and failure. The presented methods and apparatus provide PCB stiffening without the addition of external PCB stiffeners and without effecting the PCB overall thickness, fiber to matrix ratio, uniform properties, or dielectric properties.
Abstract:
A circuit board includes an electrical insulator layer formed of a reinforcer sheet with density distribution in its in-plane direction, an electrical conductor filled in a plurality of inner via holes provided in the electrical insulator layer in its thickness direction, and a wiring layer connected to the electrical conductor. The inner via holes provided in a high-density portion of the reinforcer sheet are formed to have a smaller cross-section than the inner via holes provided in a low-density portion of the reinforcer sheet. In this manner, it is possible to provide a circuit board that can achieve a high-density wiring and an inner via connection resistance with less variation, when a base material including a reinforcer sheet with density distribution in its in-plane direction such as a glass-epoxy base material is used for an insulator layer.
Abstract:
Prepregs, laminates, printed wiring board structures and processes for constructing materials and printed wiring boards that enable the construction of printed wiring boards with improved thermal properties. In one embodiment, the prepregs include substrates impregnated with electrically and thermally conductive resins. In other embodiments, the prepregs have substrate materials that include carbon. In other embodiments, the prepregs include substrates impregnated with thermally conductive resins. In other embodiments, the printed wiring board structures include electrically and thermally conductive laminates that can act as ground and/or power planes.
Abstract:
A circuit board includes an electrical insulator layer formed of a reinforcer sheet with density distribution in its in-plane direction, an electrical conductor filled in a plurality of inner via holes provided in the electrical insulator layer in its thickness direction, and a wiring layer connected to the electrical conductor. The inner via holes provided in a high-density portion of the reinforcer sheet are formed to have a smaller cross-section than the inner via holes provided in a low-density portion of the reinforcer sheet. In this manner, it is possible to provide a circuit board that can achieve a high-density wiring and an inner via connection resistance with less variation, when a base material including a reinforcer sheet with density distribution in its in-plane direction such as a glass-epoxy base material is used for an insulator layer.
Abstract:
A rigid flex printed circuit board wherein the flex section of said board comprises a basestock composite with edges formed by laminating a conductive layer to a flexible insulator layer, the conductor layer containing at least one conductive pathway and the flexible insulator layer comprises fibers dispersed in a matrix polymer. The fibers are oriented with respect to the conductive pathway so that the conductive pathway is substantially non-aligned with said fibers, substantially along an entirety of the conductive pathway in the flex section so as to be flexible.
Abstract:
The invention relates to a method of making a composite laminate comprising the steps of providing unidirectionally oriented parallel fibres (UD filaments) (3) with a resin matrix to form a composite UD layer and laminating a plurality of UD layers to form a UD crossply laminate (18). In the method of the invention, the UD filaments are impregnated with a melt of a resin which in the uncured form solidifies below a certain temperature (Tm). Thereupon the UD filaments-containing resin is cooled to a temperature below Tm to produce the composite UD layer. The produced composite UD layer is irreversibly cured before or after lamination. Notably latent curing resins are suitable. The impregnation is preferably conducted by coating a process belt (8) with solid resin (6), laying the UD filaments onto the resin, and heating the resin so as to form the resin melt. The heating of the resin is preferably conducted by means of IR irradiation (11).
Abstract:
The invention relates to a method of manufacturing a composite laminate, preferably a cross-ply laminate, in which process unidirectionally oriented (UD) fibres (3) are provided with matrix material (7) and, together with a pre-formed non-flowing UD composite or cross-ply laminate, passed through a laminating zone (13) in layers of at least two different orientational directions. More particularly, the invention relates to the manufacture of composite material which is pre-eminently suited to be used as a supporting substrate for printed wire boards. The method according to the invention is directed in particular to the utilisation of a double belt press, both for making the preformed non-flowing UD composite and for the manufacture of the final laminate. The invention also comprises printed wire board (PWBs) and multilayer PWBs.
Abstract:
A process for manufacturing a multi-layer printed wire board, also referred to as a multilayer, comprising at least two electrically insulating substrates with electrically conductive traces or layers provided on at least three surfaces thereof, in which process, by means of lamination under pressure, a cured basic substrate based on a UD-reinforced synthetic material, provided on either side with traces, is combined with and bonded to a back-up substrate, wherein during the laminating process the back-up substrate is added to the basic substrate, the back-up substrate comprising a UD-reinforced cured core layer provided at least on the side facing the conducting traces of the basic substrate with a still plastically deformable (flowable) adhesive layer, and such a pressure is exerted on the laminate as to bring said cured core layer of the back-up substrate into contact or practically into contact with the conducting traces of the basic substrate, and the space between these traces is filled with the adhesive material, so bonding the basic substrate and the back-up substrate.