Abstract: In the manufacture of ceramic circuit boards having ceramic or metal support substrates, a bonding glass layer that is adherent both to the substrate material and to multilayer green tape compositions having circuitry printed thereon, is deposited and flowed onto the support substrate. The bonding glasses suitable for use with nickel plated metal substrates and green tape compositions containing forsterite-cordierite-type glasses are mixed oxides including calcium, zinc and boron as well as other oxides. These bonding glasses have a thermal coefficient of expansion that is larger than said metal substrate, and a flow temperature below that of said cordierite-type glasses.

Abstract: Electrical feedthroughs in printed circuit board support substrates for use in making double sided ceramic multilayer printed circuit boards are made by insulating the feedthrough openings with a first layer of nickel oxide and one or more layers of glass, and then filling the remainder of the feedthroughs with a conductive metal via fill ink. After firing, the resultant structure provides insulated electrical feedthroughs through the support substrate.

Abstract: Conductive via fill inks for green tapes to be stacked and bonded to a support substrate, the glass used for the green tape having a firing temperature from 850.degree.-950.degree. C., wherein the glass used for the via fill ink has a glass transition temperature that is higher than that of the glass used to make the green tape, preferably does not crystallize at the maximum firing temperature of the green tape and comprises from 30-75 percent by volume of the glass-conductive metal powder mixture of the via fill ink. These conductive via fill inks will not shrink until the green tape shrinkage has commenced during firing of the composite circuit board and they will flow slightly during firing, forming good bonds to the glass in the walls of the vias, thereby ensuring good integrity of the vias and good connections to the circuitry on the fired ceramic multilayer circuit board.

Abstract: The present invention relates broadly to any type of multi-layered, co-fired, ceramic-on-metal circuit board, as a new article of manufacture.The present invention is more specifically directed to various compositions of MgO-13 B.sub.2 O.sub.3 --SiO.sub.2 system glass-ceramics and compositions of such glass-ceramic and suitable fillers, which are suitable for use in the fabrication of multi-layered, co-fired, ceramic-on-metal circuit boards, in which the co-fired, multi-layered ceramic exhibits desirable electrical properties and a temperature coefficient of expansion which closely matches that of its co-fired metal base, although these compositions may have other uses.

Abstract: A novel ceramic green tape composition useful in the manufacture of silver conductor based, low temperature, co-fired multilayer circuit boards comprises from about 8-35% by weight of a calcium-zinc-aluminum-borosilicate devitrifying glass; from about 10-35% by weight of a low alkali borosilicate glass; from about 10-35% by weight of a lead-zinc-aluminosilicate glass; from about 10-35% by weight of a ceramic filler; up to 0.5% by weight of a coloring agent and from about 20-45% by weight of an organic binder. The co-fired multilayer circuit boards made from these green tape compositions have excellent mechanical and electrical properties and have thermal expansion characteristics matching that of silicon.The devitrifying glass comprises from about 10-30% by weight of zinc oxide; from about 10-20% by weight of calcium oxide; up to about 15% by weight of boron oxide; from about 15-20% by weight of aluminum oxide and about 25-55% by weight of silicon oxide.

Abstract: An improved method of fabricating thick film dielectrics and copper conductors comprises depositing and drying an appropriate thick-film ink, treating the resulting patterned layer with a carbon dioxide plasma until substantially all of the organic vehicle is removed therefrom and then firing the layer in an inert atmosphere. In an alternate embodiment, a dried dielectric ink is initially treated with an oxygen plasma until about 75 to 99 percent of the vehicle is removed. Multilayer copper-based circuit structure fabricated utilizing the subject method are characterized by excellent integrity of the dielectric layers.

Abstract: A high voltage transformer for a video display apparatus includes a bobbin-wound tertiary winding. The bobbin incorporates integral nonmetallic terminal posts about which the winding segment wire is wound and terminated. The winding segments are interconnected by electrical components. The component leads incorporate a solder coating and are flattened to provide a large bonding area with the wire on the terminal posts. The component lead overlays the winding segment wire and is joined thereto by a fusion bonding process. The fusion bonding removes the wire insulations and melts the component lead solder coating to form a reflow solder joint.

Abstract: A method of testing the adhesion between a coating and its substrate applies a force to a sample by means of a plunger and supporting ring apparatus. The force is increased laterally while the force and the resulting deflection are measured. When the slope of the force-deflection curve changes abruptly, the test is terminated, and the value of force required to produce that condition is noted. The test is nondestructive.