Abstract:
A prepreg useful in flame resistant copper clad printed circuit boards is made by impregnating a porous substrate with an impregnant containing: either a prebrominated epoxy resin or a mixture of a non-halogenated epoxy resin and flame retarding additive containing bromine, and phenolic hydroxyl groups. A phenolic novolac oligomer having an average of over 2.5 phenolic hydroxyl groups per oligomeric unit is used as curing agent. Optionally, a suitable catalyst may be included. The impregnated substrate is heated to cure or advance the resin to the "B"-stage.
Abstract:
Increased elasticity of a laminate is obtained by adding 5-20% by weight of a blocked polyetherurethane component from a reaction product of polyethylene glycol, polypropylene glycol and p-nonylphenol with toluene-2,4-diisocyanate having the following composition:______________________________________ polyethylene glycol 15-20% by weight polypropylene glycol 50-60% by weight toluene-2,4-diisocyanate 8-12% by weight nonylphenol 10-15% by weight ______________________________________ in the manufacture of a fire resistant laminate based on a cellulose-containing substrate material and an impregnating varnish made up of a phenol-resol with additives of plasticizers and flame retardants. A copper-laminated hard paper made of this phenolic resin laminate is distinguished by reduced punching resistance and stripping resistance.
Abstract:
A continuous process for producing reinforced resin laminates comprising the steps of impregnating a fibrous substrate with a liquid resin which is free of volatile solvent and is capable of curing without generating liquid and gaseous byproducts, laminating a plurality of the resin-impregnated substrates into a unitary member, sandwiching the laminate between a pair of covering sheets, and curing the laminate between said pair of covering sheets without applying appreciable pressure. The improvement comprises adjusting the final resin content in said resin impregnated substrate at 10 to 90% by weight based on the total weight of said impregnated substrate.
Abstract:
A laminate comprising at least one inorganic or organic fiber nonwoven fabric impregnated with a cyanic acid ester resin composition, at least one glass fabric impregnated with an epoxy resin composition, and at least one of the outermost layers being the glass fabric impregnated with an epoxy resin composition.
Abstract:
A method of improving the dimensional and thermal stability of a fibrous web containing substrate is disclosed. A uniformly or randomly spun or bonded fabric or textile support is impregnated with a curable polymer resin, e.g., an epoxy-polyester resin. The impregnated resin is then fully cured whereupon a polymer resin coat is applied thereto. The coat is maintained in a partial cure state whereby a laminate comprising an internal woven or bonded fabric skeleton impregnated with a fully cured polymer resin and coated with a layer of a partially cured polymer resin is obtained.
Abstract:
A method of fabricating a thermal printing head by printing a circuit pattern of resistive elements and electric conductors on one surface of a flat paper sheet, covering the circuit pattern and surface of the flat paper sheet with a carrier layer of a substantially transparent methacrylic acid resin, peeling off the flat paper sheet, placing the remaining carrier layer carrying the circuit pattern over a surface of a pre-shaped insulating substrate with the circuit pattern being laid downward, and heating the carrier layer placed on the substrate to cause the carrier layer to be burned off and cause the circuit pattern to adhere to the surface of the substrate.
Abstract:
In a printed circuit board, on which there are formed printed components such as resistors and capacitors and printed conductors, which comprise silver or silver powder and resin, such as an electrode of a component and a connecting conductor, there are provided under coating layer and/or an over coating layer comprising insulating resin and an organic inhibitor so as to prevent migration of silver from the conductor of a higher potential to the conductor of a lower potential.
Abstract:
The disclosed laminate is suitable for use in the art of printed circuitry and comprises an electrically conductive layer and a nonwoven backing layer. The nonwoven backing has unusual dimensional stability under a wide variety of conditions and preferably comprises a blend of at least 15 wt. % polyester staple and at least 10 wt. % aromatic polyamide staple. This blend is impregnated with a thermosettable resin.
Abstract:
Wood derived multilayer glued or laminated product having an integrated electric circuit, comprising a paper layer and conducting elements of conductive ink deposited on said paper layer, said elements being suitable for forming an electric circuit and said paper layer has a rugosity inferior to 60 μm. The paper layer may be of kraft paper. The product may comprise one or more additional kraft paper layers, in particular having a hole for receiving electric components such that the top surface of product remains flat. The product may include a fibreboard substrate of MDF. The paper layer may be a decorative paper layer glued with the circuit facing the substrate. The manufacture process comprises depositing conductive ink elements on a paper layer having rugosity inferior to 60 μm for forming an electric circuit; and incorporating, by gluing or laminating, said paper layer into the multilayer product.
Abstract:
Disclosed is a printed circuit board, to which at least one circuit device is mountable, including a base layer with a plurality of paper layers; a waterproof insulation layer laid on a first surface of the base layer; a copper foil layer laid on a second surface opposite to the first surface of the base layer and printed with a signal line pattern connectable with the at least one circuit device; and an adhesive layer configured to be interposed between the base layer and the copper foil layer that includes an adhesive material for adhering the base layer and the copper foil layer.