Abstract:
A method for coating cloth especially fiberglass sheets with a thermosetting resin and resulting structure is provided. The coating is performed in two steps. In the first step, essentially all of the strands of the fiberglass are coated with the resin/solvent mixture while maintaining at least some of the interstices or openings essentially free of the solvent mixture. This first coating is then partially cured to between about 70% and 90% of full cure. The coated fiberglass with partially cured resin thereon is then given a second coating of either the same or different thermosetting resin mixture which coats the first coating and fills in the interstices between the fibers. This second coating is then partially cured, which advances the cure of the first coating past 80% full cure and results in an impregnated fiberglass cloth structure for use as sticker sheets. During lamination, the first coating acts like an impenetrable insulating sheet, preventing resin displacement and, therefore, preventing glass fiber contact with the conductive planes. The second coating is fluid enough to fill in spaces in the planes and to form the adhesive bond to cores and conductive layers. The structure reduces the tendency of the resin to flake and produce dust during subsequent processing operations.
Abstract:
A method for coating cloth especially fiberglass sheets with a resin and resulting structure is provided. The coating is performed in two steps. In the first step, essentially all of the strands of the fiberglass are coated with the resin solvent mixture as well as most of the interstices or openings, although some of the interstices or openings have holes where the coating does not completely fill in. This first coating is then partially cured to the extent that it will not redissolve in a second coating of the same resin solution. The coated fiberglass with partially cured resin thereon is then given a second coating of the same resin mixture which coats the first coating and fills in any holes in the first coating. This second coating is then partially cured, which advances the cure of the first coating and results in an impregnated fiberglass cloth structure for use as sticker sheets. This substantially reduces pinholing.
Abstract:
A method and resultant article are provided which optimize the adhesion of resin to the glass fibers in fiberglass cloth impregnated with a resin and also optimize the adhesion of the impregnated resin to metal sheets laminated to the resin-impregnated cloth. The fiberglass is treated in two or more passes. On the first pass, the fiberglass is impregnated with a first resin which is optimized for adherence to glass fibers and the coated resin is partially cured. In a last pass, the fiberglass is impregnated with a second resin, which is different from said first resin, and is optimized for bonding to metal. The second resin is then partially cured. The first and second resins are selected such that they form a bond with each other when cured.
Abstract:
A method for coating cloth especially fiberglass sheets with a resin and resulting structure is provided. The coating is performed in two steps. In the first step, essentially all of the strands of the fiberglass are coated with the resin solvent mixture while maintaining the interstices or openings essentially free of the solvent mixture. This first coating is then partially cured to the extent that it will not redissolve in a second coating of the same resin solution. The coated fiberglass with partially cured resin thereon is then given a second coating of the same resin mixture which coats the first coating and fills in the interstices between the fibers. This second coating is then partially cured, which advances the cure of the first coating and results in an impregnated fiberglass cloth structure for use as sticker sheets. During lamination, the first coating acts like an impenetrable insulating sheet, preventing resin displacement and, therefore, preventing glass fiber contact with the conductive planes. The second coating is fluid enough to fill in spaces in the planes and to form the adhesive bond to cores and conductive layers.
Abstract:
The present invention provides an improved method for forming a patterned solder mask having preferred electric insulating property, heat resistance-and chemical resistance on a printed circuit board with high resolution.
Abstract:
A method of patterning metal on a substrate without photolithography. The steps include providing a dielectric substrate, forming a metal mask in a predetermined pattern on the substrate without using a mask by direct-write deposition using a particle beam such as a liquid metal cluster force to form the mask, dry etching the substrate to form a plurality of channels therein, depositing a conductive metal into the channels, and removing the mask. The top of the substrate can then be planarized by polishing, or alternatively the dielectric between the metal lines can be etched. The invention is well suited for fabricating copper/polyimide substrates.
Abstract:
A laser lithography process for semiconductor interconnect and semiconductor manufacture having the advantages of non-contact printing processes and being much faster than prior art laser lithography processes is disclosed. In accordance with the process, a metal layer to be patterned either for use as a patterned metal layer or as a mask for patterning a layer therebelow, such as a think polyimide layer, is first coated with a very thin layer of polymer evaporated as a monomer using a vapor deposition process. This provides a very thin layer of polymer over the metal layer, which thin polymer layer is readily and quickly patterned by laser to provide a mask for the subsequent chemical etching of the metal layer. The vapor deposited polymer layer, while being very thin and thus readily removed by laser, is also substantially fault free, thereby providing a high-quality mask for the chemical etching process free of any possible damage from ordinary sources such as mask aligners, etc., yet being readily removed when desired such as by way of example, by plasma etching thereof. Various methods and applications are disclosed.
Abstract:
In the manufacture of printed circuit boards, a first photoresist post is patterned on the substrate where via holes are to be made. A dielectric layer is put down, a second photoresist layer patterned so as to have openings over and in alignment with the photoresist posts, and the dielectric removed from the via holes. Barrier layers to reduce interaction between layers of copper, dielectric and photoresist during filling of the via holes with a conductor via fill ink are also described.
Abstract:
According to a preferred embodiment, arbitrarily shaped holes are fabricated in 0.1 to 2 mm thick plates of polyoxymethylene homo- or copolymers. For that purpose, the polymeric substrate is photoresist-coated on either side; the desired pattern is simultaneously applied to both the front and the back side of the photoresist layers by imagewise exposure at optimum mask alignment; the photoresist layers are developed and blanket-exposed; the resultant photoresist structures are treated with a cyclic organosilicon compound and postbaked; the through holes are produced by sequential reactive ion etching of the polyoxymethylene from the front and the back side, each time down to a depth of about 2/3 of the substrate thickness; and the silylated photoresist masks are stripped from the front and the back side of the substrate.
Abstract:
A masking for use in connection with the manufacture of circuit board comprising a polyvinyl alcohol film, which is uniformly annealed to be free of stress and strains and which is water-soluble at a temperature of 120.degree. F. A water-soluble adhesive, having a stiffness of between about medium soft and about medium, is placed on the film, and the masking material has a moisture level of below about 2% by weight.