Abstract: Methods of analyzing and controlling an electroless plating solution are described which provide for real time control of the electroless plating solution, e.g., an electroless copper bath whose main constituents are copper sulfate, complexing agent, formaldehyde, a hydroxide and a stabilizer. All necessary constituent concentrations, particularly the reducing agent concentration, are measured in situ and may be used to analyze and/or control the composition of the bath. A control cycle of less than one minute is required and hence real time control is achieved. The in situ measurements also provide quality indicia of the copper quality factors which are likewise used to control composition of the bath. Data from the in situ measurements is fed to a computer which, in turn, controls additions to the bath to maintain a bath composition which provides good quality electrolessly formed, copper plating.

Abstract: A process for preparing a ceramic substrate for metallization wherein a surface of the ceramic substrate is contacted with a composition containing one or more alkali metal compounds, preferably in the form of solid pellets. The pellets are melted on the ceramic surface. As the pellets melt, advancing waves of the molten composition spread across and wet the ceramic surface. The molten alkali metal composition is kept in contact with the ceramic surface for a time period sufficient to etch the surface and thus prepare it for adherent deposition of metal. The moving waves of melting composition supply fresh alkali metal compounds at the ceramic surface. After adhesion promotion, the ceramic surface is treated with compounds that promote adsorption of catalyst for metal deposition before being plated with metal. Uniform surface coverage with catalyst and metal and an improved adherent bond of metal to the ceramic surface are obtained.

Abstract: A process for avoiding blister formation between a metal layer which is electrolessly deposited on a surface of a ceramic substrate and the substrate. The substrate is adhesion promoted with an alkali metal composition containing between 0.35 and 0.9 mole fraction alkali metal compound, and water in an amount which is sufficient to lower the melting temperature of the composition to between 145.degree. and 240.degree. C. and adhesion promote the ceramic surface with the molten composition in a time period between 1 and 200 minutes. Thereafter, the adhesion promoted ceramic surface may be activated to render it receptive to electroless metal deposition. The treated ceramic surface is coated free of blisters using an electroless metal deposition bath with an adherent, metal layer having a thickness greater than 5 micrometers.

Abstract: An article comprised of metal directly and adherently bonded onto a ceramic substrate, and a process for producing same, wherein the ceramic is adhesion promoted with molten inorganic compound, treated with halide compounds that promote adsorption of catalyst for metal deposition, and plated with metal. Uniform surface coverage with catalyst and metal is ensured by the halide treatment.

Abstract: An article comprised of metal directly and adherently bonded onto a ceramic substrate, and a process for producing same, wherein the ceramic is adhesion promoted with molten inorganic compound, treated with compounds that promote adsorption of catalyst for metal deposition, and plated with metal. Uniform surface coverage with catalyst and metal is ensured by the treatment with the adsorption promoters.

Abstract: There is provided a method for increasing the useful effective plating rate of an electroless copper deposition solution which comprises copper ion, a complexing agent for copper ion, a reducing agent and a pH adjustor and which is characterized by a plating rate which first increases and passes through a peak plating rate and then decreases as a function of a pH above 10. In accordance with this invention, the plating rate of such a solution may be significantly increased by operation thereof in the presence of an accelerating or depolarizing agent at a pH to achieve a plating rate above the plating rate of the solution without such an agent at the same pH. The accelerating or depolarizing agents for use herein include compounds containing a delocalized pi-bond, such as heterocyclic aromatic nitrogen and sulfur compounds, non-aromatic nitrogen compounds having at least one delocalized pi-bond, and aromatic amines.

Abstract: Electroless metal deposition solutions are provided which comprise, in combination, an ion of a metal whose electroless metal deposition is desired; a complexing agent for said ion; a reducing agent for said ion; a pH regulator; and less than about 25 parts per million of metal ions which have an oxidation potential greater than the oxidation potential of the ion of the metal whose electroless deposition is desired.