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:
The present invention provides a method for making a metallic pattern on a substrate having a surface comprising bare metal in predetermined areas and metal coated by a resist in remaining areas which comprises (i) protecting the bare metal by coating with a film-forming resin, (ii) removing any film-forming resin from the resist, (iii) removing the resist from said remaining areas using a solvent which will not remove the film-forming resin, thereby exposing metal in said remaining areas, (iv) etching the metal exposed in (iii) using an etchant which does not remove the film-forming resin and (v) removing the film-forming resin with a suitable solvent.
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:
This invention relates to an adhesion promoting composition and method for its use for promoting adhesion of printed circuits on thermoplastic substrates. The composition includes isopropanol with either methylene chloride or resorcinol. An added ingredient includes polycyclohexanone. The preferred substrate is polyarylsulfone.
Abstract:
Cette invention concerne une composition d'un masque de soudure pour des substrats thermoplastiques. Le masque de soudure possède des composants critiques qui comprennent un polyhydroxyéther et une formaldéhyde de mélanine. D'autres composants consistent en un solvant, un matériau de charge et un agent de régulation de la fluidité. D'éventuels ingrédients sont un colorant, une résine époxyde et de l'acide pour contribuer à la réaction de la composition. Un agent tensio-actif peut également être incorporé. Le masque de soudure confère aux plaquettes de circuit thermoplastiques la flexibilité et l'adhésion nécessaires. Le masque peut être appliqué directement sur une plaquette de circuit ou sur un milieu de transfert pour le recouvrement ultérieur d'un substrat. Elle concerne un article qui peut être une plaque à circuit imprimé. Elle concerne également un procédé de fabrication de tels composites qui inclut le traitement du masque de soudure.
Abstract:
The present invention provides a method for making a metallic pattern on a substrate having a surface comprising bare metal in predetermined areas and metal coated by a resist in remaining areas which comprises (i) protecting the bare metal by coating with a film-forming resin, (ii) removing any film-forming resin from the resist, (iii) removing the resist from said remaining areas using a solvent which will not remove the film-forming resin, thereby exposing metal in said remaining areas, (iv) etching the metal exposed in (iii) using an etchant which does not remove the film-forming resin and (v) removing the film-forming resin with a suitable solvent.
Abstract:
Compositions comprising phenolic end-capped polyimides and epoxy resins containing at least two 1,2-epoxy groups per resin molecule are fusible and/or soluble in polar solvents, for use in forming protective passivation coatings on e.g. electrical components. Preferred polyimides are polysiloxane-modified. The coatings are resistant to solvent and solder flux.
Abstract:
A printing ink for solder resist used in the production of printed circuit boards contains a given amount of a silicon resin and/or fluororesin in addition to ink components.
Abstract:
The invention concerns a coating composition which may be used to form a peelable solder mask. The coating composition comprises a mixture of vinylic resin, microcrystalline wax and solvent. Applied as a film coating, the coating composition can be used to provide a temporary mask to selected areas of a substrate, for example, a printed circuit, prior to exposure to a solder flux, the mask being readily peelable from the substrate.