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: 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: A method of fabricating a multi-layered, co-fired, ceramic-on-metal circuit board utilizes a bonding layer of glass. The glass has a coefficient of thermal expansion not greater than that of the metal base. The glass of the bonding layer has a softening point below that of the glass in the multi-layer ceramic so that the glass of the bonding layer flows and bonds to the metal to minimize the lateral shrinkage of the multi-layered ceramic.

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: A novel devitrifying glass comprising, in weight percent, from 5-15% of zinc oxide, from 10-18% of magnesium oxide; from 15-20% of calcium oxide; from 6-14% of barium oxide; from 15-20% of aluminum oxide and from 30-40% of silicon dioxide. The glasses are thermally matched to alumina substrates. The glasses form overglaze thick film inks when admixed with an organic vehicle that are useful as protective coatings for alumina substrates and multilayer printed circuits.

Abstract: Low-expansion devitrifying glass compositions exhibiting a negative-slope temperature coefficient of expansion over a temperature range from about 125.degree. C. to about 500.degree. C. are useful for the fabrication of thick film copper via-fill inks for multilayer printed-circuit boards.

Abstract: In the manufacture of printed circuit boards, a first photoresist post is patterned on the substrate where via holes are to be made. A dielectric layer is put down, a second photoresist layer patterned so as to have openings over and in alignment with the photoresist posts, and the dielectric removed from the via holes. Barrier layers to reduce interaction between layers of copper, dielectric and photoresist during filling of the via holes with a conductor via fill ink are also described.

Abstract: An improved dielectric formulation for the fabrication of multilayer, integrated circuits which comprises a devitrifying zinc-magnesium-barium-aluminum-zirconium-phosphosilicate glass frit, a devitrifying zinc-magnesium-barium-aluminum-silicate glass frit, or a devitrifying zinc-magnesium-strontium-aluminum-silicate glass frit which are stabilized by the presence of from about 0.01 to about 1 weight percent each of lead oxide and iron oxide.

Abstract: Improved copper conductor inks useful in the fabrication of multilevel circuits are disclosed. The inks comprise copper powder, a devitrifying glass frit selected from a zinc-calcium-aluminum-silicate glass frit, a zinc-magnesium-barium-aluminum-silicate glass frit and mixtures thereof, an adhesion promoting oxide, and a suitable organic vehicle. These inks are particularly adapted for applications where superior adhesion between the copper conductor ink and the underlying substrate or dielectric film is required.

Abstract: Improved copper conductor inks useful in fabricating multilevel circuits are provided. The inks comprise copper powder, a devitrifying glass frit which does not begin to flow until the furnace temperature is above about 700.degree. C., and a suitable organic vehicle. Devitrifying glass frits with these properties include a zinc-calcium-aluminum-silicate glass frit, a zinc-magnesium-barium-aluminum-silicate glass frit, a zinc-magnesium-barium-aluminum-zirconium-phosphosilicate glass frit and mixtures thereof. The inks are advantageous in that they form copper conductor layers having excellent properties without the inclusion of traditional flux materials such as bismuth oxide.

Abstract: A novel devitrifying frit is disclosed which has a coefficient of expansion essentially the same as that of silicon. The subject frits have a high softening temperature and excellent reheat stability which make them useful in ink formulations for forming dielectric layers in multilayer circuitry. The frits are also suitable for use as a substrate material for direct mounting of silicon chips or for use in thick film via-fill inks.

Abstract: An improved dielectric ink for the fabrication of multilayer integrated circuits is disclosed. The subject inks comprise a devitrifying magnesium-barium-aluminum-zirconium-borophosphosilicate glass frit, an organic vehicle and, optionally, a suitable ceramic filler material. Dielectric layers and stand-alone substrates formed from the subject inks are characterized by good mechanical strength, heat resistance and exceptional density. The subject inks are particularly useful in the fabrication of multilayer circuit structures based on copper since their exceptional density renders them resistant to penetration by flux materials from the copper conductor layers.

Abstract: Improved copper conductor inks useful in the fabrication of multilevel circuits are disclosed. The inks comprise copper powder, a devitrifying glass frit selected from a zinc-calcium-aluminum-silicate glass frit, a zinc-magnesium-barium-aluminum-silicate glass frit and mixtures thereof, an adhesion promoting oxide, and a suitable organic vehicle. These inks are particularly adapted for applications where superior adhesion between the copper conductor ink and underlying substrate or dielectric film is required.

Abstract: An improved copper via-fill ink for forming post-ups in a thick dielectric layer separating two patterned layers of copper conductor in a multilayer circuit assembly is provided. The via-fill ink comprises copper powder, a suitable organic vehicle and a glass frit consisting of a devitrifying glass and a vitreous glass. The devitrifying glass is a zinc-magnesium-barium-aluminum-zirconium-phosphosilicate glass and the vitreous glass is a barium-calcium-borosilicate glass.

Abstract: Improved copper conductor inks useful in fabricating multilevel circuits are provided. The inks comprise copper powder, a devitrifying glass frit which does not begin to flow until the furnace temperature is above about 700.degree. C., and a suitable organic vehicle. Devitrifying glass frits with these properties include a zinc-calcium-aluminum-silicate glass frit, a zinc-magnesium-barium-aluminum-silicate glass frit, a zinc-magnesium-barium-aluminum-zirconium-phosphosilicate glass frit and mixtures thereof. The inks are advantageous in that they form copper conductor layers having excellent properties without the inclusion of traditional flux materials such as bismuth oxide.

Abstract: An improved dielectric ink for the fabrication of multilayer, integrated circuits is disclosed. The subject inks comprise a devitrifying zinc-magnesium-barium-aluminum-zirconium-phosphosilicate glass frit, a devitrifying zinc-magnesium-barium-aluminum-silicate glass frit, or a devitrifying zinc-magnesium-strotium-aluminum-silicate glass frit, an organic vehicle and, optionally, a suitable ceramic filler material. The subject glass frit containing a suitable ceramic filler can be fabricated into stand-alone substrates useful in a wide variety of electronic applications. The glass frit of the subject inks has a high softening temperature which facilitates complete removal of carbonaceous residues of the vehicle from the dried ink during firing. This is advantageous in that it eliminates the need to incorporate oxygen-generating additives, such as barium nitrate, in the ink or treatment of the ink in an oxidizing or reducing plasma prior to firing.

Abstract: A novel devitrifying frit is disclosed which has a coefficient of expansion essentially the same as that of silicon. The subject frits have a high softening temperature and excellent reheat stability which make them useful in ink formulations for forming dielectric layers in multilayer circuitry. The frits are also suitable for use as a substrate material for direct mounting of silicon chips or for use in thick film via-fill inks.

Abstract: An improved dielectric ink for the fabrication of multilayer, copper-based integrated circuits is disclosed. The subject inks comprise a suitable ceramic filler material, an organic vehicle and a lead-zinc-aluminum-borosilicate glass frit. Dielectric layers formed from the subject inks are characterized by exceptional resistance to the penetration therein by flux materials such as PbO and Bi.sub.2 O.sub.3 from conventional copper conductors during repeated firings.

Abstract: Low-expansion devitrifying glass compositions exhibiting a negative-slope temperature coefficient of expansion over a temperature range from about 125.degree. C. to about 500.degree. C. are useful for the fabrication of thick film copper via-fill inks of multilayer printed-circuit boards.