Abstract: A printed circuit board or card for direct chip attachment that includes at least one power core, at least one signal plane that is adjacent to the power core, and plated through holes for electrical connection is provided. In addition, a layer of dielectric material is adjacent the power core and a circuitized conductive layer is adjacent the dielectric material, followed by a layer of photosensitive dielectric material adjacent the conductive layer. Photodeveloped blind vias for subsequent connection to the power core and drilled blind vias for subsequent connection to the signal plane are provided. Also provided is process for fabricating the printed circuit board or card for direct chip attachment.

Abstract: Disclosed is a method of drilling, desmearing, and additively circuitizing a printed circuit board. The printed circuit board is drilled under conditions which produce glass and polymer smeared vias and through holes. The particulate debris is removed by vapor blasting the drilled printed circuit board. Next the printed circuit board is soaked in a solvent to swell the drill smear on the circuit interplanes of the printed circuit board. This solvent is then removed by entrainment in a gas, and a stream of an aqueous, acidic, oxidizing solution is passed through the printed circuit board holes to remove swollen smear in the thru holes and produce an etchback of conductors. After a water rinse an aqueous reducing solution is passed through the printed circuit board to reduce and remove aqueous acidic oxidizing solution, e.g., residual aqueous acid oxidizing solution. The printed circuit board is rinsed to remove the aqueous reducing solution.

Abstract: Copper is deposited onto a substrate by plating a first layer of copper onto the substrate from an electroless plating bath and plating a second layer of copper onto the first layer of copper from a second and different electroless plating bath. The first and second plating baths differ from each other in at least the cyanide content and oxygen content. The process reduces plating void defects and reduces nodule formation.

Abstract: Process for treating liquid waste compositions which contain copper ions and a complexing agent for the copper which includes reducing the concentration of copper ions in the waste solution to less than about 8 ppm and contacting the solution with an ozone-containing gas and irradiating with ultraviolet light.

Abstract: A cleaning process for high aspect ratio through holes of multilayer printed circuit boards assures the removal of any loosened fiberous material or epoxy smears in the through holes and also provides an inverted "T" structure at the innerplanes of the internal conductive circuits within the printed circuit board sandwich. The inverted "T" structure helps to move the contact point between the plating of the through hole and the internal circuit lines further into the circuit board, thereby eliminating the "Z" stress at the edge of the innerplane.

Abstract: Copper is electrolessly deposited on a surface wherein the dissolved oxygen content is maintained between 2 and 4 ppm in the plating bath.