Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
2000-11-16
2001-11-27
Dawson, Robert (Department: 1712)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C523S442000, C523S457000, C523S458000, C523S459000, C523S460000, C523S468000
Reexamination Certificate
active
06322620
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to an electrically conductive ink composition having improved properties for use in various electronic applications.
BACKGROUND OF THE INVENTION
Many different forms of electronic devices employ printed circuit boards having electronically conductive ink compositions. Conductive ink compositions are screen printable and are used to form conductive elements in electronic applications. For example, conductive inks are utilized as screen-printed electronic circuitry in through hole connection, jumpers, printed board wiring and similar electronic applications to provide stable electrical interconnections. Most currently available conductive inks generally consist of phenolic resin. Some currently available conductive inks also contain an epoxy resin or a mixture of resins, such as acetylacetone with cyanic acid ester resin or acrylic resin with melamine resin. Such compositions also contain electrically conductive filler materials which are dispersed in the resins and which remain an integral part of the final composition after processing.
There are many drawbacks to currently available conductive inks. One such drawback is that many conductive inks have very short shelf-lives at room temperature. These inks are very difficult to transport and store. Shipping, in particular, is quite difficult in that the inks must be maintained within a coolant, such as dry ice for the duration of the transit. A further drawback of conductive inks is that they frequently require high drying and curing temperatures and relatively long drying and curing times. Consequently, it would be advantageous to develop a conductive ink which would exhibit long shelf life at room temperatures. It would further be advantageous to provide an ink which would require lower drying and curing temperatures at shorter drying and curing times.
Additional properties are also desired in a thermoset conductive ink. One such desired property is that the conductive ink be sufficiently conductive, or have low electrical resistivity, to carry an electric current when cured. Other desired properties are that the conductive ink have good abrasion and chemical resistance when cured so that it is not easily scratched or wiped off by solvent and that it have acceptably good adhesion to the substrate, commonly a copper substrate, when cured. Further, it is desired that the conductive ink provides good rheology for good screen printability and is stable at relatively high temperatures on the substrate so that it is not affected by any heat treatment which may be necessary.
Accordingly, it would be advantageous to provide a conductive ink which provides a long shelf life at room temperature, low drying and curing temperatures and short drying and curing times. It would be further advantageous to provide such a conductive ink which provides the other desired benefits of a conductive ink.
REFERENCES:
patent: 3745045 (1973-07-01), Brenneman
patent: 4479890 (1984-10-01), Prabhu
patent: 4535012 (1985-08-01), Martin
patent: 4552690 (1985-11-01), Ikeguchi
patent: 4564563 (1986-01-01), Martin
patent: 4962139 (1990-10-01), Lo
patent: 5061551 (1991-10-01), Durand
patent: 0140585 (1984-09-01), None
patent: 0143530 (1984-09-01), None
patent: 2135673A (1984-02-01), None
patent: 50022582 (1975-03-01), None
patent: 60004552 (1985-01-01), None
patent: 64056777 (1987-08-01), None
patent: 125311 (1988-03-01), None
patent: 63089577 (1988-03-01), None
patent: 63057677 (1988-04-01), None
patent: 04268381 (1988-12-01), None
patent: 2155113 (1988-12-01), None
patent: 01085248 (1989-03-01), None
patent: 01098674 (1989-04-01), None
patent: 01174573 (1989-07-01), None
patent: 01193106 (1991-03-01), None
patent: 04016973 (1992-01-01), None
patent: 04081469 (1992-03-01), None
patent: 05117419 (1993-05-01), None
patent: 05225822 (1993-09-01), None
patent: 9240168 (1996-03-01), None
patent: 9265953 (1997-03-01), None
patent: WO 91/20088 (1991-12-01), None
Kessenikh, R.M.;Temperature Dependence of the Electrical Conductivity of Modified and Plasticized Epoxy Compounds Heat-Cured In Strong Fields; Izv. Vyssh. Ucheb. Zaved., Fiz. (1969); 12(10; 133-6; Russia.
Anonymous; Rapid Curing of Adhesives in Precise Locations by Conduction Heating.
Sancaktar, E.; Electric Resistive Heat Curing of the Fiber-Matrix Interphase in Graphite/Epoxy Composite; Journal of Mechanical Design; pp. 53-60; Mar. 1993, vol. 115.
Plapp, Nile; A Vapor Phase Solution for Curing Conductive Epoxy Adhesives; Surface Mount Technology; 48-50; Aug. 1993.
Sancaktar, E; Electric Resistive Heat Curing of the Fiber-Matrix Interphase in Graphite/Epoxy Composites DE-vol. 30, Reliability, Stress Analysis and Failure Prevention ASME 1991; pps127-137.
Almer Charles W.
Aylward D.
Dawson Robert
National Starch and Chemical Investment Holding Corporation
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