General Electric Company

Robert E Belke, Jr

Louis Zakraysek

Raymond A Shirk

Walter O Pillar

David P Smith

Hsiu H Lin

Richard J Hill

George F Trojanowski

Disclosed are improved laminates useful in the manufacture of multi-layer printed wiring boards (MLPWB) and laminates. Such improved composites contain at least one layer which is formed from a liquid crystal polymer selected from the group consisting of poly(para-phenylene benzobisthiazole), poly(paraphenylene benzobisoxazole), poly(2,5-benzothiazole), poly(2,5-benzoxazole), and mixtures thereof. The presently preferred liquid crystal polymer comprises poly(para-phenylene benzobisthiazole). The negative coefficient of thermal expansion and high modulus of elasticity of the liquid crystal polymers enable a laminate and MLPWB to be manufactured therefrom having a tailored coefficient of thermal expansion, broadly ranging from about 0 to 15 ppm/.degree. C. MLPWBs constructed of polymeric core layers also are possible utilizing the preferred liquid crystal polymers of the present invention.

Tailorable multi-layer printed wiring boards of controlled coefficient

The invention relates to a metal matrix composite used to support and/or enclose discrete electronic semiconductor devices, monolithic integrated circuits, hybrid circuits, and multi-layer printed wiring boards. The matrices herein disclosed employ aluminum as the matrix with Beta Eucryptite as the additive in a volume percent of up to 60. The preferred range of from 55 to 45 percent by volume of the additive has a coefficient of thermal expansion matching the common semiconductor materials and common ceramics used for electronic enclosures. The composite uses low cost materials, and due to the affinity of the additive to aluminum is easily prepared. The resulting structures have good thermal conductivity and low weight.

Metal matrix composite and structure using metal matrix composites for

A novel metal core printed circuit board and a method of making it are described. The circuit board comprises a metal substrate, a patternable metal foil, and an insulating layer of thermoplastic resin whose glass transition temperature is exceeded during assembly under pressure to bond the resin to the metal substrate and to the foil by high temperature wetting. The circuit board also provides holes whose interior is lined with a resin united fusing to the resin in the insulating layer by high temperature wetting accompanied by pressure. The thermoplastic resin is a polyetherimide engineering plastic. The layers of the printed circuit board described above, including any additional layers of insulating resin and foil, may be bonded in a single step in a laminating press. The finished circuit board may be a structural component of a chassis, has good heat conductivity, good high voltage performance, is practical for high frequency transmission paths, is tolerant of the high temperature necessary for soldering, and has a high continuous service temperature.

Metal core printed circuit board

The invention deals with a method of electroding a poly(vinylidene fluoride) solid in a piezoelectric application. The electroding method entails surface preparation of the poly(vinylidene fluoride) by a variety of steps including plasma etching to create temporary molecular scale surface irregularities followed by sputtering a metallic layer before deterioration of the plasma etched surface. The chromium may be the initial metal sputtered, followed by a sputtered copper layer, followed in turn by at least one heavier electrodeposited conductive layer. The method may be conducted without deterioration of the piezoelectric properties of the material. The method has been found to provide very good adhesion between the electrode and the PVF.sub.2 surface.

Method of electroding a poly(vinylidene fluoride) solid

The invention deals with a method of bonding a poly(vinylidene fluoride) solid to a variety of solid substrates, in an application typically using the piezoelectric properties of the material. The bonding method entails surface preparation of the poly(vinylidene fluoride) by a variety of steps including activation of the surface by plasma etching to cause the surface to wet the adhesive used in the bonding process. The bonding method produces bonds of increased strength and having good electrical properties.

Growing community of inventors

Clay, NY, United States of America

Robert E Belke, Jr