World Properties, Inc.

Rogers Corporation

Doris I Hand

Michael E St Lawrence

Vincent R Landi

Samuel Gazit

Robert H Walker

Raymond R Miskiavitch

Allen F Horn, Iii

Scott D Kennedy

Michael S White

E Clifford Roseen, Jr

A method for the manufacture of a multilayer circuit comprising a liquid crystalline polymer layer, the method comprising treating the multilayer circuit with an amount of heat effective to raise the crystalline to nematic melting point, as defined by the peak endotherm above the glass transition temperature in a differential scanning calorimeter measurement, of the liquid crystalline polymer layer by at least about 10&#xb0; C.

Method for making a multilayer circuit

An electrical substrate material is presented comprising a thermosetting matrix of polybutadiene or polyisoprene in an amount of about 15 to about 50 volume %; a fabric reinforcement in an amount of 0 to about 40 volume %; a particulate filler, preferably ceramic, in an amount of from 0 to about 60 volume %; microballoons in an amount from 0 to about 60 volume %; and optionally a flame retardant. A peroxide cure initiator and/or crosslinking agent may optionally be added. The presence of a very high surface area particulate filler, preferably fumed silica, is also preferred, in that its presence results in a prepreg which has very little tackiness and can therefore be easily handled by operators. This low tackiness feature allows for the use of conventional automated layup processing, including foil cladding, using one or more known roll laminators. While the prepreg of this invention is tack-free enough to be handled relatively easily by hand, it is also tacky enough to be tacked to itself using a roll laminator (e.g., nip roller) at room temperature. The composition of this invention is particularly well suited for making electrical circuit substrates for microwave and digital circuits, typically in the form of the thermosetting composition being laminated onto one or both opposed surfaces to a metal conductive foil such as copper.

Polybutadiene and polyisoprene thermosetting compositions and method of

An electrical substrate material is presented comprising a thermosetting matrix of polybutadiene or polyisoprene and a co-curable second resin distinct from the first resin. A peroxide cure initiator and/or crosslinking agent may optionally be added. The presence of a very high surface area particulate filler, preferably fumed silica, is also preferred, in that its presence results in a prepreg which has very little tackiness and can therefore be easily handled by operators. This low tackiness feature allows for the use of conventional automated layup processing, including foil cladding, using one or more known roll laminators. While the prepreg of this invention is tack-free enough to be handled relatively easily by hand, it is also tacky enough to be tacked to itself using a roll laminator (e.g., nip roller) at room temperature. The composition of this invention is particularly well suited for making electrical circuit substrates for microwave and digital circuits, typically in the form of the thermosetting composition being laminated onto one or both opposed surfaces to a metal conductive foil such as copper.

An electrical substrate material is presented comprising a thermosetting matrix of polybutadiene or polyisoprene in an amount of 25 to 50 volume %; a woven glass fabric in an amount of 10 to 40 volume %; a particulate, preferably ceramic filler, in an amount of from 5 to 60 volume %; and a flame retardant. Importantly, the composition comprises only a single resin, i.e., polybutadiene or polyisoprene. A peroxide cure initiator and/or crosslinking agent may optionally be added. The presence of a very high surface area particulate filler, preferably fumed silica, is also preferred, in that its presence results in a prepreg which has very little tackiness and can therefore be easily handled by operators. This low tackiness feature allows for the use of conventional automated layup processing, including foil cladding, using one or more known roll laminators. While the prepreg of this invention is tack-free enough to be handled relatively easily by hand, it is also tacky enough to be tacked to itself using a roll laminator (e.g., nip roller) at room temperature. The composition of this invention is particularly well suited for making electrical circuit substrates for microwave and digital circuits, typically in the form of the thermosetting composition being laminated onto one or both opposed surfaces to a metal conductive foil such as copper.

Single resin polybutadiene and polyisoprene thermosetting compositions

An electrical substrate material is presented which comprises a thermosetting matrix which includes a polybutadiene or polyisoprene resin and an unsaturated butadiene or isoprene containing polymer in an amount of 25 to 50 vol. %; a woven glass fabric in an amount of 10 to 40 vol. %; a particulate, preferably ceramic filler in an amount of from 5 to 60 vol. %; a flame retardant and a peroxide cure initiator. A preferred composition has 18% woven glass, 41% particulate filler and 30% thermosetting matrix. The foregoing component ratios and particularly the relatively high range of particulate filler is an important feature of this invention in that this filled composite material leads to a prepreg which has very little tackiness and can therefore be easily handled by operators. This low tackiness feature allows for the use of conventional automated layup processing, including foil cladding, using one or more known roll laminators. While the prepreg of this invention is tack-free enough to be handled relatively easily by hand, it is also tacky enough to be tacked to itself using a roll laminator (e.g., nip roller) at room temperature. In addition, another important feature of this invention is the low amount of glass fabric filler relative to the higher range of particulate filler which leads to improved (lower) CTE in the Z axis or thickness direction, improved electrical performance (e.g., dissipation factor), lower cost and the ability to tailor dielectric constant through appropriate selection of particulate fillers.

Growing community of inventors

Dayville, CT, United States of America

Doris I Hand