US5126192A
Expired / Lapsed
US
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Flame retardant, low dielectric constant microsphere filled laminate
Assignee: International Business Machines Corp
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Filing: 1990-01-26
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Granted: 1992-06-30
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Expires: 2010-01-26
Abstract
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.
Inventors
- 👤 Leroy N. Chellis
- 👤 Robert M. Japp
- 👤 William J. Summa
- 👤 William J. Rudik
- 👤 David W. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:31
CPC Classifications
C; C08; C08K; C08K7/00; C08K7/22; C08K7/24; C08J; C08J5/00; C08J5/24; C08J5/246; C08J5/248; C08J5/249; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/0373; H05K1/0366; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/012; H05K2201/02; H05K2201/0203; H05K2201/0206; H05K2201/0209; H05K2201/0239; H05K2201/0242; H05K2201/0254; H05K2201/0275; H05K2201/029; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/25; Y10T428/29; Y10T428/2982; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
97 words
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.
Claim 2
Dependent Claim
97 words
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.
Claim 3
Dependent Claim
34 words
The prepreg material recited in claim 1 wherein the hollow inorganic microspheres of the filler are randomly distributed and exhibit a compressive strength of between about 500 to about 5000 pounds per square inch.
Claim 4
Dependent Claim
43 words
The prepreg material recited in claim 1 wherein the reinforcement material comprises a woven cloth, mat or film selected from the group consisting of glass, ceramic, fluoropolymer, polyester, quartz, polyimide, Kevlar, Nomex, poly p-phenylene benzobisthiazole, poly p-phenylene benzobisoxazole, Aramid, polyetheretherketone, and aromatic polyester.
Claim 5
Dependent Claim
21 words
The prepreg material recited in claim 1, wherein the polymer resin and hollow inorganic microsphere filler comprise a flame retardant material.
Claim 6
Dependent Claim
23 words
The prepreg material recited in claim 1, comprising in addition a UV blocking dye for rendering the laminate opaque to UV wavelength light.
Claim 7
Dependent Claim
47 words
The prepreg material recited in claim 2, wherein about 90% of the hollow inorganic microspheres of the filler are glass or silica walled and have a mean diameter between about 5 microns to about 25 microns and comprise about 2% by weight or less of sodium oxide.
Claim 8
Dependent Claim
25 words
The prepreg material recited in claim 6 wherein the hollow glass microspheres of the filler comprise from about 25 to about 65 percent by volume.
Claim 9
Dependent Claim
118 words
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.
Claim 10
Dependent Claim
118 words
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.
Claim 11
Dependent Claim
19 words
The prepreg material recited in claim 1, comprising in addition a substance which imparts flame retardance to the material.
Claim 12
Dependent Claim
20 words
The prepreg material recited in claim 9, wherein the substance which imparts flame retardance comprises an antimony or halogen compound.
Claim 13
Dependent Claim
22 words
The prepreg material recited in claim 9, wherein the substance which imparts flame retardance comprises a brominated polyglycidyl ether of bisphenol A.
Claim 14
Dependent Claim
28 words
The prepreg material recited in claim 10 wherein the polymer resin is an epoxy and the halogen compound comprises about 19% to about 23% by weight of bromine.
Claim 15
Dependent Claim
30 words
The prepreg material recited in claim 1, wherein the polymer resin is an epoxy resin and the microspheres are present in an amount between about 37 and 46% by volume.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-30 | 1995-12-30 | 1996-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-30 | 1999-12-30 | 2000-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-30 | 2003-12-30 | 2004-06-30 | $7700.00 | Window Closed / Lapsed |