Abstract: A liquid crystalline composite comprising a liquid crystalline polymer, particulate filler, and fibrous web. Further disclosed is a method for forming the liquid crystalline polymer composite. The liquid crystalline polymer composite is useful in circuit materials, circuits, and multi-layer circuits, economical to make, and has excellent flame retardant properties.

Abstract: A liquid crystalline composite comprising a liquid crystalline polymer, particulate filler, and fibrous web. Further disclosed is a method for forming the liquid crystalline polymer composite. The liquid crystalline polymer composite is useful in circuit materials, circuits, and multi-layer circuits, economical to make, and has excellent flame retardant properties.

Abstract: A load beam for a suspension assembly comprises a liquid crystal polymer layer disposed between and in intimate contact with a first metal layer and a second metal layer, preferably stainless steel. Such load beams have improved dimensional and hygrothermal stability, as well as greater ease of processing over conventional load beams, allowing tailoring of bend and flex properties.

Abstract: A load beam for a suspension assembly comprises a liquid crystal polymer layer disposed between and in intimate contact with a first metal layer and a second metal layer, preferably stainless steel. Such load beams have improved dimensional and hygrothermal stability, as well as greater ease of processing over conventional load beams, allowing tailoring of bend and flex properties.

Abstract: A method of making liquid crystalline polymer-copper laminates comprising laminating liquid crystalline polymer film to a copper foil wherein the copper foil has a surface concentration of zinc of less than or equal to about 2 atomic % and a surface concentration of chromium of less than or equal to about 4 atomic %, based on surface atomic concentration. Preferably the copper foil further comprises a dendritic layer. The copper foil may optionally be coated with a hydrophobic layer prior to lamination. The liquid crystalline polymer/copper laminate exhibits significantly improved bond strength retention compared to the prior art, particularly after being subjected to conditions of high humidity and temperature for 24 hours or more.

Abstract: The present invention is a liquid crystal polymer suspension assembly. This assembly comprises a stainless steel layer and an electrically conductive layer with a dielectric liquid crystal polymer layer disposed therebetween and bonded thereto. Due to controlled coefficient of thermal expansion, modulus, and very low moisture absorption of the liquid crystal polymer, the suspension assembly of the present invention will have improved dimensional and hygrothermal properties over conventional assemblies, enabling higher density, higher performance assemblies to be produced.

Abstract: Methods of fabricating multilayer circuits are presented. In accordance with the present invention, a plurality of circuit layers are stacked, one on top of the other. At least one of the circuit layers comprise a substrate composed of a polymeric material capable of undergoing bonding such as a fluoropolymeric based substrate having vias therethrough and a circuit comprised of a layer of suitable conductive material. A fusible conductive bonding material (e.g., solder) or a noble metal is applied wherever electrical connections are desired. At least one other of the circuit layers comprises a cofired multilayer ceramic circuit having vias and circuits comprised of a layer of suitable conductive material with a fusible conductive bonding material (e.g., solder) or a noble metal applied wherever electrical connections are desired.

Abstract: Methods of fabricating multilayer circuits are presented. In accordance with the present invention, a plurality of circuit layers are stacked, one on top of the other. At least one of the circuit layers comprise a substrate composed of a polymeric material capable of undergoing bonding such as a fluoropolymeric based substrate having vias therethrough and a circuit comprised of a layer of suitable conductive material. A fusible conductive bonding material (e.g., solder) or a noble metal is applied wherever electrical connections are desired. At least one other of the circuit layers comprises a polyimide circuit (or other high temperature non-fusing polymer circuit, with or without filler or fabric reinforcement) having vias and circuits comprised of a layer of suitable conductive material with a fusible conductive bonding material (e.g., solder) or a noble metal applied wherever electrical connections are desired.

Abstract: In accordance with the present invention, an MCM substrate product is manufactured in an additive process using multiple layers of a fluoropolymer composite material and copper. The copper layers are plated, and the fluoropolymer composite layers are laminated. A seeding process promotes reliable bonding between the fluoropolymer composite material and the plated copper. The use of the filled fluoropolymeric composite eliminates the need for a barrier metal layer between the insulation and the conductors. The MCM substrate device of the present invention may have multiple metal layers and multiple dielectric layers; four or five, or more, of each in a single structure would be easily achieved and is typical. The structure would include lead lines in separate mutually orthogonal planes (sometimes referred to as "x" and "y" lead lines) sandwiched between ground and power voltage planes of copper.

Abstract: A flexible circuit is presented having a flexing (cyclic bending) section of lower stiffness than adjacent parts of the circuit. The lower stiffness in the flexing section is achieved by reducing the thickness of the flexing section, either by omitting or removing some or all of the dielectric material of the flexible circuit in the flexing section, or by replacing conventional dielectric material in the flexing section with a polymer of lower modulus of elasticity.

Abstract: A method of ablating fluoropolymer composite materials is presented wherein it has been found that small holes (less than 100 .mu.m) can be formed in fluoropolymer composite laminate materials using UV lasers. The resulting holes can be used to produce vias and plated through-holes having smooth side walls with little or no debris or residue remaining in the holes and minimal damage to the polymer. Thus, the vias and plated through-holes can be plated without further cleaning processes. In addition, the holes are formed at a relatively fast rate.

Abstract: A preferably low dielectric constant polymeric bonding layer is applied or bonded (i.e., laminated or coated) to at least one side of a preferably low dielectric constant polymeric delay line substrate. Preferably, the melting or softening point of the bonding film is lower than the melting or softening point of the substrate so that the application (e.g. lamination) step is carried out at a temperature which is above the softening point of the bonding film, but below the softening point of the substrate (thereby insuring the integrity of the delay line circuit). Thereafter, the delay line/bonding layer assembly is rolled up and head sealed so as to melt the bonding layer, thus heat sealing the delay line package. As the package heats up (in, for example, a tightly fitting die), the materials expand and provide sufficient pressure to bond the circuit together.

Abstract: Inductive devices, i.e., transformers, coils, inductors, etc. are produced from a rolled flexible circuit. The flexible circuit is comprised of a dielectric substrate having a circuit pattern thereon. The circuit pattern is configured such that, upon rolling, one or more coils is formed thereby defining an inductor, transformer, etc. Additionally, these inductive devices may be easily shielded using a ground plane in the flexible circuit. The rolled flexible circuit may be secured in several ways including an adhesive or by using a thermoplastic bonding layer which acts to heat seal the circuit together. The inductive devices of the present invention may be wrapped or rolled about a permeable core which improves inductance. Inductor devices manufactured in accordance with the present invention have the advantages of being small, surface mountable, inexpensive to manufacture and being capable of insertion onto printed wiring boards using automated insertion equipment.

Abstract: A process for the preparation of extrudable polyimide granules comprising heating and compacting a powder containing polyimide particles to form a partially densified porous mass and crushing the mass to form granules which may be ram extruded to give uniform articles of high strength.

Abstract: An aqueous developable subtractive printing plate is presented comprising a photosensitized hydrophilic surface having a photosensitive diazo-borofluoride salt thereon.A method for making a photosensitized printing plate is also presented wherein a photosensitive diazo-borofluoride salt is coated on the plate.