Abstract:
Quaternary ammonium bicarbonates are suitable for use as catalysts in curable epoxy compositions. The curable compositions prepared therewith are used to prepare coated substrates, and to produce conformally sealed printed wiring boards and flexible circuits. Methods for preparation and curing are also provided. Of particular utility are compositions comprising benzytrimethyl ammonium bicarbonate.
Abstract:
Compositions and processes for the preparation of printed circuits from epoxy compositions are provided. The epoxy compositions exhibit low viscosity in the uncured state and low coefficient of thermal expansion in the cured state. The low dielectric constant compositions of the invention are well-suited for use in multi-layer printed circuit boards.
Abstract:
Compositions and processes for the preparation of printed circuits from epoxy compositions are provided. The epoxy compositions exhibit low viscosity in the uncured state and low coefficient of thermal expansion in the cured state. The low dielectric constant compositions of the invention are well-suited for use in multi-layer printed circuit boards.
Abstract:
The present invention relates to an apparatus and a process for a half-cell structure to make a hexagonal-cell honeycomb core. The structure has a plurality of peaks and valleys and a diagonal surface between each consecutive peak and valley. The apparatus comprises a stack holder for stacking the structure so that as one sheet is placed on top of a stack comprising at least one sheet, the peaks of one sheet contact the peaks of an adjacent sheet. The apparatus also comprises an air blower disposed beneath the top of the stack for reducing the air pressure surrounding the stack to a pressure below the air pressure on the top of the stack, thereby pressing the layers together to form the core.
Abstract:
Provided is a film having a thickness of less than 500 μm comprising a polymer and a plurality of surface-modified hexagonal boron nitride particles dispersed therewithin. The polymers can be polyimide or epoxy. A process for preparing the film by casting is provided.
Abstract:
Quaternary ammonium bicarbonates are suitable for use as catalysts in curable epoxy compositions. The curable compositions prepared therewith are used to prepare coated substrates, and to produce conformally sealed printed wiring boards and flexible circuits. Methods for preparation and curing are also provided. Of particular utility are compositions comprising benzytrimethyl ammonium bicarbonate. The curable composition is coated onto a first film or sheet, including a polyimide film or sheet. The coated sheet is then contacted to the surface of second film or sheet, where preferably there are discrete metallic conductive pathways disposed thereupon.
Abstract:
Provided is a composite comprising a polymer and a plurality of surface-modified hexagonal boron nitride particles dispersed therewithin. Suitable polymers include polyimide and epoxy. A process is also provided. The surface modified hexagonal boron nitride particles comprise surface-bonded substituted phenyl radicals.
Abstract:
Epoxy compositions exhibiting low viscosity in the uncured state and low coefficient of thermal expansion in the cured state are provided. Also provided are processes for making the epoxy compositions. The low dielectric constant compositions are well-suited for use in multi-layer printed circuit boards. The desired properties are achieved by employment of a bimodal distribution of nano-scale fillers in the epoxy compositions.