Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-12-10
2004-02-03
Brunsman, David (Department: 1755)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C501S138000, C501S139000, C343S785000, C343S907000
Reexamination Certificate
active
06686406
ABSTRACT:
TECHNICAL FIELD
The present invention relates to electrical parts, for example, they are dielectric antenna, such as a microwave antenna used for mobile communications and walkie-talkies; condensers, filters, and printed circuit substrate for the high-frequency range of microwaves or higher frequency. In addition, the present invention relates to a manufacturing method for the above mentioned electrical parts, such as an antenna.
Further, the present invention relates to a dielectric ceramic suitable for dielectrics of such electrical parts, and resin-ceramic composite material.
BACKGROUND ART
As a conventional material for a microwave antenna, a condenser, a filter, and a printed circuit substrate for high-frequency use, ceramics made by baking are mainly used. The baked ceramics have an advantage that they can attain a high dielectric constant (∈) and a low dielectric dissipation factor (tan &dgr;), compatibly. However, the conventional material is never free from an antinomic relation that a composition whose change in dielectric constant owing to change of temperature (i.e. temperature dependence) is small, causes a low dielectric constant. Further, the baked ceramic material has defects that they require a baking step to be conducted at a temperature above 1,000° C., they have difficulty in post-processing, because of hardness and brittleness, and they have difficulty in post-forming a metal pattern (the pattern is formed by means of converting a paste of a metal, such as silver, drawn in a pattern beforehand, into a metal itself, at the baking step).
On the other hand, a composite material, comprising a resin blended with a ceramic powder, has been developed (for example, JP-A-8-69712 (“JP-A” means unexamined published Japanese patent application)). The composite material obtained in this way has an advantage of being readily processable (i.e. a general method for molding resins can be employed). However, the dielectric constant generally decreases when a ceramic is powderized. As such, the conventional composite material blended with a ceramic powder has a disadvantage of a low dielectric constant.
Further, there is a problem in the composite material that, when a conventional ceramic with a high dielectric constant is employed, to raise the dielectric constant of a composite material, the temperature dependency of dielectric constant of the composite material increases, as in the case of the said baked ceramic. On the other hand, when a ceramic with a large particle size, or a fiber-shaped ceramic, is used for the purpose of maintaining a dielectric constant as high as possible, the composite material becomes inferior in formability and difficulty of forming a minute metal pattern when used for a printed circuit substrate.
Additionally, a resin-ceramic composite material, using polyphenylene sulfide (PPS) as a resin, is described in JP-A-9-36650. The PPS is highly evaluated for its low tan &dgr;. However, an investigation by the present inventors revealed that there was still room to reduce changes of characteristics by moisture absorption. Namely, it was found that reduction of the changes of tan &dgr; and ∈ by moisture absorption was desirable. However, these points were not studied in the above-mentioned JP-A-9-36650.
In addition, as PPS was a resin hard to plate thereon, because it had high chemical resistance and therefore it exhibited low adhesion strength to adhesives. As such, the use of a resin-ceramic composite material using PPS for electrical parts, such as a dielectric antenna, has been very limited.
To solve this kind of problem, a method of using a ceramic powder with a limited particle size, ranging from 1 to 10 &mgr;m, and plating the obtained PPS resin composition, after a surface treatment, by wet etching with solvent or solution, is disclosed in JP-A-61-183473. However, a wet etching has a disadvantage in cleaning, after the treatment was performed. In addition, a solvent that can etch PPS is extremely limited to specific ones, and such special solvents are not good for workers, because of harmful effects on the human body and a foul odor. In JP-B-56-25453 (“JP-B” means examined published Japanese patent application), a method, in which plating is carried out after physical etching and a modification of PPS surface by a treatment with an oxidizing solution, is also disclosed. However, there is the same problem as above because the oxidizing solution is also extremely limited to such specific solutions.
The above-mentioned and other and further features, and advantages of the invention will appear more fully from the following description, taken in connection with the accompanying drawings.
REFERENCES:
patent: 5962122 (1999-10-01), Walpita et al.
patent: 56-25453 (1981-12-01), None
patent: 61-183473 (1986-08-01), None
patent: 06-223625 (1994-08-01), None
patent: 8 69712 (1996-03-01), None
patent: 09-036650 (1997-02-01), None
patent: 11-060274 (1999-03-01), None
patent: 97/20332 (1997-06-01), None
Ishiwa Masayuki
Tomomatsu Isao
Brunsman David
Knobbe Martens Olson & Bear LLP
The Furukawa Electric Co. Ltd.
LandOfFree
Dielectric ceramic, resin-ceramic composite material,... 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 ceramic, resin-ceramic composite material,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dielectric ceramic, resin-ceramic composite material,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3353442