Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
1999-12-09
2003-08-19
Ball, Michael W. (Department: 1733)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S763000
Reexamination Certificate
active
06608760
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention (Technical Field)
The present invention relates to a dielectric substrate useful in the manufacture of printed wiring boards wherein the dielectric substrate comprises at least one organic polymer having a T
g
greater than 140° C. and at least one filler material. The dielectric substrate of this invention has a dielectric constant that varies less than 15% over a temperature range of from −55 to 125° C. This invention also includes multilayer printed circuit boards including dielectric substrates of this invention and especially printed circuit boards wherein the dielectric substrate of this invention is used to form internal distributed capacitors in the printed circuit board.
2. Background Art
Multilayer printed wiring boards (PWB's) are widely used in electronic devices such as computers, telephones, appliances, automobiles and the like. Multilayer printed wiring boards typically include a board having a plurality of insulated conductive trace layers separated by dielectric substrate layers. Due to the demand for smaller and smaller electronic devices, efforts have been made to incorporate circuit devices directly into printed wiring boards. For example, U.S. Pat. No. 5,010,641 discloses a multilayer printed wiring board including internal distributed capacitors. Similarly, U.S. Pat. Nos. 5,155,655 and 5,161,060 disclose capacitor laminates useful in the manufacture of capacitive printed wiring boards.
The capacitors built into printed wiring boards typically include a metal ground layer and a charged metal layer divided by a dielectric substrate layer. The dielectric layers used in printed wiring board capacitors are generally polymeric sheets that may be reinforced with materials such as glass, ceramics and so forth. More recently, there has been a trend towards reducing the profile of circuits and dielectric layers in printed wiring boards in order to increase printed wiring board circuit density. This trend has resulted in the reduction of the thickness of dielectric layers associated with wiring board capacitors. However, a problem with reducing the thickness of capacitor dielectric layers is that the dielectric constant of the dielectric layer varies too widely with varying temperatures causing undesirable variable capacitance. Therefore, there remains the need for dielectric substrate layers that are useful in forming printed wiring board capacitors that are thin and have dielectric constants that vary little over a wide temperature range.
SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)
A primary object of the present invention is to provide a dielectric substrate that has a dielectric constant that varies little over a wide temperature range.
Another primary object of the present invention is to provide a dielectric layer that includes a non-sintered particular material.
Another primary object of the present invention is to provide a capacitor laminate including a dielectric sheet having an essentially unchanging dielectric constant which is located between conductive foil layers.
A primary advantage of the present invention is a composite comprising at least one organic polymer having a T
g
greater than about 140° C., and at least one ferroelectric particle filler. The organic polymer and ferroelectric particles are chosen to produce a composite having a dielectric constant that varies less than 15% when the composite is subjected to temperatures ranging from −55 to 125° C.
Another primary advantage of the present invention is a capacitor laminate comprising a composite of this invention formed into a sheet and having a top surface and a bottom surface. The capacitor laminate includes a first conductive layer associated with the composite top surface, and a second conductive layer associated with the composite bottom surface.
Another primary advantage of the present invention includes multi-layer printed wiring boards wherein at least one layer comprises a capacitor laminate of this invention.
REFERENCES:
patent: 3290756 (1966-12-01), Dreyer
patent: 3304475 (1967-02-01), Gowen et al.
patent: 3593107 (1971-07-01), Chilton et al.
patent: 3673092 (1972-06-01), Dietz
patent: 4000054 (1976-12-01), Marcantonio
patent: 4087300 (1978-05-01), Adler
patent: 4294009 (1981-10-01), Quintin et al.
patent: 4306273 (1981-12-01), Maylandt et al.
patent: 4490429 (1984-12-01), Tosaki et al.
patent: 4520004 (1985-05-01), Uedaira et al.
patent: 4558020 (1985-12-01), Itakura et al.
patent: 4764493 (1988-08-01), Lilley et al.
patent: 4775573 (1988-10-01), Turek
patent: 4816072 (1989-03-01), Harley et al.
patent: 4827377 (1989-05-01), Butt
patent: 4829033 (1989-05-01), Menashi et al.
patent: 4832939 (1989-05-01), Menashi et al.
patent: 4859448 (1989-08-01), Klee et al.
patent: 4863883 (1989-09-01), Menashi et al.
patent: 4882455 (1989-11-01), Sato et al.
patent: 4908258 (1990-03-01), Hernandez
patent: 4942079 (1990-07-01), Kumagai et al.
patent: 4943469 (1990-07-01), Kumagai et al.
patent: 4943606 (1990-07-01), Inoue et al.
patent: 4952538 (1990-08-01), Kumagai et al.
patent: 4987108 (1991-01-01), Takagi et al.
patent: 4999740 (1991-03-01), Ilardi et al.
patent: 5010641 (1991-04-01), Sisler
patent: 5079069 (1992-01-01), Howard et al.
patent: 5112433 (1992-05-01), Dawson et al.
patent: 5155655 (1992-10-01), Howard et al.
patent: 5161086 (1992-11-01), Howard et al.
patent: 5162977 (1992-11-01), Paurus et al.
patent: 5172304 (1992-12-01), Ozawa et al.
patent: 5256470 (1993-10-01), Jean et al.
patent: 5261153 (1993-11-01), Lucas
patent: 5428499 (1995-06-01), Szerlip et al.
patent: 5445806 (1995-08-01), Kinugasa et al.
patent: 5451426 (1995-09-01), Abe et al.
patent: RE35064 (1995-10-01), Hernandez
patent: 5469324 (1995-11-01), Henderson et al.
patent: 5504993 (1996-04-01), Szerlip et al.
patent: 5555486 (1996-09-01), Kingon et al.
patent: 5569488 (1996-10-01), Frankosky
patent: 5604018 (1997-02-01), Horiuchi et al.
patent: 5638252 (1997-06-01), Drab et al.
patent: 5796587 (1998-08-01), Lauffer et al.
patent: 5800575 (1998-09-01), Lucas
patent: 5870274 (1999-02-01), Lucas
patent: 5926377 (1999-07-01), Nakao et al.
patent: 5972231 (1999-10-01), DiBene, II
patent: 5973929 (1999-10-01), Arakawa et al.
Uchino, Kenji, et al, “Particle/Grain Size Dependence of Ferroelectricity”,Ceramic Dielectrics,1989, pp. 107-115 (copy already attached to amendent).
Hartman William F.
Law Kristen J.
Slenes Kirk M.
Baker Rod D.
Ball Michael W.
Fain Katy C.
Haran John T.
Peacock Deborah A.
LandOfFree
Dielectric material including particulate filler does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dielectric material including particulate filler, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dielectric material including particulate filler will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3116676