Circuit board prepreg with reduced dielectric constant
US5670250A · kind A · utility
46Cited by
16References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 16, 1995 |
| Grant date | Sep 23, 1997 |
| Priority date | — |
| Expiry date | May 16, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31663
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention involves a prepreg composition and procedure for use in forming printed circuit boards with reduced and uniform dielectric constant, improved thermal expansion characteristics, and uniform appearance. The prepreg composite is a resin impregnated substrate and has a reduced dielectric constant as low as 3.5. It contains 5-30% by resin volume of hollow inorganic microsphere filler whose diameters are less than 40 micrometers, and the uniform distribution of the hollow inorganic microspheres is controlled by the presence of hydrophobic fumed silica or other similar flow modifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.