Abstract: A crystal resonator assembly is described wherein a piezo-electric resonator is mounted over a heat conducting substrate and one or more heat generating elements are located on the substrate. The heating elements provide heat both by conduction and radiation and by virtue of the use of a heat conducting substrate enable a uniform and efficient heating of the crystal resonator to a desired oven temperature.

Abstract: An electronic circuit having an electrically conductive pattern formed on a substrate and having on at least one surface of the substrate a film obtained from a soluble polymerizable oligomer of the formula: ##STR1## wherein D is ##STR2## wherein M is --C.tbd.C--, --C.tbd.C--C.tbd.C, --O--, ##STR3## wherein R is an alkyl or aromatic group; wherein Ar is an aromatic group; wherein x is an integer greater than two but less than 30, z is either zero or an integer, and y is an integer wtih the sum of y and z equal to x; and wherein n is an integer from 1 to 10. The substrate is coated by applying the above composition to the substrate and then hardening the composition by further polymerization. Preferred compositions contain the above described oligomer and certain plasticizers and/or toughening agents.

Abstract: An electronic circuit having an electrically conductive pattern formed on a substrate and having on at least one surface of the substrate a film obtained from a soluble polymerizable oligomer of the formula: ##STR1## wherein M is --C.tbd.C--, --C.tbd.C--C.tbd.C, --O--, ##STR2## wherein R is an alkyl or aromatic group; wherein Ar is an aromatic group; wherein X is an integer greater than two but less than 30, z is either zero or an integer, and y is an integer with the sum of y and z equal to x; and wherein n is an integer from 1 to 10. The substrate is coated by applying the above composition to the substrate and then hardening the composition by further polymerization. Preferred compositions contain the above described oligomer and certain plasticizers and/or toughening agents.

Abstract: An improved wire enamel consisting essentially of the following materials by weight wherein basis is wire enamel weight; at least 50% by wt. of a polar organic solvent; about 2-8% by wt. of a polyimide precursor which can be cured to yield a polyimide polymer; about 0.5 to about 25% by weight of the substituted aliphatic hydrocarbon solvent for the polyimide precursor having a surface tension and polarity greater than that of the halogenated aliphatic hydrocarbon described below or a substituted aromatic hydrocarbon having a dipole moment less than or equal to the dipole moment of the halogenated aliphatic hydrocarbon described below; about 5 to 40% by wt. of a halogenated aliphatic hydrocarbon; and 0 to about 1% by wt. of an organosilane which increases the adhesion of the polyimide to an underlying substrate.

Abstract: This invention describes a method of masking a workpiece to prevent the adhesion of a deposited tightly adhering conformal coating formed from the condensation of a vaporous diradical such as paraxylylene on selected portions of the workpiece. Specifically the process of the invention requires the covering of the areas of the workpiece, to which adhesion is not desired, with a non-polymerizing hydrocarbon and placing the covered area in close contact with an open cellular material containing a predominance of interconnecting cells which provides a large surface area for condensation of the unwanted condensate of the diradical, exposing the workpiece to the vaporous diradical, removing the workpiece from the open cellular material and immersing the workpiece in a solvent for swelling and dissolving the hydrocarbon covering.