Flame retardant, low dielectric constant microsphere filled laminate
AssigneeInternational Business Machines Corporation
InventorsLeroy N. Chellis, Robert M. Japp, William J. Summa, William J. Rudik, David W. Wang
Life of this patent
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Abstract
A flame retardant, low dielectric constant, controlled coefficient of thermal expansion, low cost prepreg material which includes randomly distributed silane coated hollow microspheres has been prepared by standard impregnation and lamination techniques. Laminates made of this prepreg can be drilled cleanly for through holes and can be used as a substrate for surface mounted devices.
Claims13
A filled prepreg material having a dielectric constant below 3.2, comprising:
- about 37 volume percent to about 47 volume percent of at least one polymer resin selected from the group consisting of cyanate, epoxy, benzocyclobutene, polyimide, fluoropolymer and dicyanate;
- about 25 to about 65 volume percent of hollow inorganic microsphere filler wherein the hollow inorganic microspheres of the filler have a maximum diameter of less than 40 microns;
- a coupling agent;
- and
- about 8 to about 27 volume percent of reinforcement material, all in amounts relative to each such that the overall dielectric constant is below 3.2.
A printed circuit board comprising a prepreg material having a dielectric constant below 3.2, which material includes
- about 37 volume percent to about 47 volume percent of at least one polymer resin selected from the group consisting of cyanate, epoxy, benzocyclobutene, polyimide, fluoropolymer and dicyanate;
- about 25 to about 65 volume percent of hollow inorganic microsphere filler wherein the filler has a maximum diameter of less that 40 microns;
- a silane coupling agent;
- and
- about 8 to about 27 volume percent of reinforcement material, the circuit board also including at least one layer of conductive material disposed on at least a portion thereof, all in amounts relative to each such that the overall dielectric constant is below 3.2.
Dependencies are inferred from the claim text.