Abstract:
Disclosed is a printed circuit board which is advantageous in terms of high capacitance by embedding capacitors comprising polymer capacitor pastes with high-dielectric constant coated on an inner layer of the printed circuit board and then semi-dried to a state of B-stage.
Abstract:
The present invention relates to a method of manufacturing a metal clad laminate for printed circuit board, characterized by direct adhesion of a conductive metal foil without use of a thermosetting resin having low melting points, an adherent film or an adhesive. The method includes forming fine protrusions on at least one surface of a fluorine-based resin insulation layer, roughening one surface of a conductive metal foil, laminating the fluorine-based resin insulation layer having fine protrusions on the roughened metal foil so that the roughened surface of the metal foil and the protrusion-formed surface of the insulation layer face each other to form a laminated body, and compressing the laminated body under vacuum, pressure and heat. The method of manufacturing the metal clad laminate by directly adhering the conductive metal foil with a single dielectric structure has advantages in terms of lower manufacturing costs compared to conventional dual dielectric structures, and very stable operation of the metal clad laminate in high frequency regions due to minimized variations of electrical and mechanical properties. Thus, the present method is effective in manufacturing the printed circuit board usable in the high frequency regions.
Abstract:
A wiring transfer sheet including a carrier base and a wiring layer formed thereon is produced so that an exposed area of a surface of the carrier base on which the wiring layer is formed has a plurality of concavities. By transferring the wiring layer to an electrically insulating substrate with this wiring transfer sheet, convexities which are complementary to the concavities are formed on the electrically insulating substrate. The convexities improve adhesion between a wiring board and a resin stacked thereon. Therefore, the wiring board thus obtained has surface coplanarity suitable for mounting a semiconductor bare chip and an electronic component as a whole, and a microscopical surface structure which adheres to a material stacked thereon.
Abstract:
A printed wiring board is formed from two or more layers, one of which has circuit lines formed thereon, and wherein the surfaces of the circuit lines are roughened only in areas that require good copper to laminate adhesion. The remainder of the circuit line surfaces are smooth. Thus, those areas for propagation of the signal on signal lines have the circuit lines smooth to maximize the signal propagation effect, while those areas where the signal propagation is not critical are rough, which improves the adhesion of one layer to another. On the voltage planes, the surface in those regions opposite the smooth surfaces of the signal planes is smooth. Thus, these areas of the voltage planes can be maintained smooth while the other areas of the surface of the voltage planes can be roughened, providing good adhesion to the adjoining dielectric material.
Abstract:
The present invention provides a new device and method for enhancing the electrical properties of the thick metal backer/electrically conductive thermoset adhesive/printed circuit board or card assembly. The enhanced electrical properties are obtained by providing a thin bondline of conductive adhesive that is essentially void free.
Abstract:
A substrate and a method of making the substrate is provided. The substrate includes a layer of metal with at least one through hole therein, the layer of metal having an adhesion promoting layer thereon. A layer of a partially cured low-loss polymer or polymer precursor is positioned on the adhesion promoting layer and a plurality of conductive circuit lines are positioned on a portion of the partially cured dielectric layer. The substrate can be used as a building block in the fabrication of a multilayered printed circuit board.
Abstract:
A process for producing an electrodeposited copper foil with its surface prepared, comprising the steps of: subjecting an electrodeposited copper foil having a shiny side and a matte side whose average surface roughness (Rz) is in the range of 2.5 to 10 &mgr;m to at least one mechanical polishing so that the average surface roughness (Rz) of the matte side becomes in the range of 1.5 to 3.0 &mgr;m; and subjecting the matte side having undergone the mechanical polishing to a selective chemical polishing so that the average surface roughness (Rz) of the matte side becomes in the range of 0.8 to 2.5 &mgr;m. The invention further provides an electrodeposited copper foil with its surface prepared, produced by the above process, and still further provides PWBs and a multilayer laminate of PWBs, produced with the use of the above electrodeposited copper foil with its surface prepared. The mechanical polishing followed by chemical polishing of the matte side enables obtaining an electrodeposited copper foil with its surface prepared, the matte side of which exhibits excellent properties, and hence enables obtaining PWBs and a multilayer PWBs which have excellent properties.
Abstract:
A filet F is added to a portion constituting a corner portion C equal to or smaller than 90° in a crossing portion X of wiring patterns 58b, 58c and 58d, and a wiring pattern 58 is formed. Since the filet F is added, the wiring patterns are not made thin and are not disconnected in the crossing portion X. Further, since there is no stress concentrated to the crossing portion X, disconnection is not caused in the wiring patterns and no air bubbles are left between the crossing portion X of the wiring patterns and an interlayer resin insulating layer so that reliability of a printed wiring board is improved.
Abstract:
An attachment surface for an implantable device has a random irregular pattern formed through a repetitive masking and chemical milling process. Additionally, an attachment surface for an implantable device has a random irregular pattern formed through a repetitive masking and electrochemical milling process. The electrochemical milling process is particularly well suited for use with substrate materials which have high chemical inertness which makes them resistant to chemical etching. Surface material is removed from the implant surface without stress on the adjoining material and the process provides fully dimensional fillet radii at the base of the surface irregularities. This irregular surface is adapted to receive the ingrowth of bone material and to provide a strong anchor for that bone material. The unitary nature of the substrate and surface features provides a strong anchoring surface with is resistant to cracking or breaking. The surface is prepared through an etching process which utilizes the random application of a maskant and subsequent etching of the metallic substrate in areas unprotected by the maskant. This chemical etching process is repeated a number of times as necessitated by the nature of the irregularities required in the surface. The etching characteristics are controlled by the time, temperature and number of repetitions utilized in the etching process.
Abstract:
A method for increasing the surface area and roughness of metals, ceramics and composites on a micro-scale, and the surfaces themselves, is disclosed whereby a laser beam having a radiation wavelength of from UV to infrared is pulsed onto the surface of the material. The energy density of the radiation is between 0.01 to 15 J/cm.sup.2 and at least 50 pulses of radiation having duration of from 1 picosecond to 1 millisecond are used on each area. The surface structures formed are semi-periodic and are from 1/4 to several hundred microns in magnitude.