Abstract: The invention relates to a process, and compositions for its implementation, to promote adhesion between an inorganic substrate and an organic polymer, especially between the copper surfaces of printed circuits for electronic use and a polymer resin, in which an organometallic layer of a dark brown colour, which is very uniform and compact, is deposited on the inorganic substrate by means of treatment in a composition which comprises: a) a silane or a mixture of functional organic silanes with a structure represented by the following general formula: Y—(CH2)n—Si(OR)3 where: Y represents a functional organic group, n is a number which has a value between 0 and 3, and R represents a hydrogen atom or any easily hydrolysable group which is capable of releasing an atom of hydrogen b) an azole compound; c) an oxygen carrier; d) an organic or inorganic acid; and preferably e) a zinc compound.

Abstract: A process for manufacturing printed circuits provided with through holes, which comprises a cleaning pretreatment including a possible treatment by an organic solvent, a treatment in an alcaline solution of permanganate and a treatment for permanganate reduction, and a subsequent metallization treatment including a treatment for conditioning the walls of the through holes, a treatment for mordanting the copper surfaces, a precatalysis treatment, a catalysis treatment and a metallization treatment by a chemical copper both, wherein three treatments, namely reducing the permanganate, conditioning the walls of the through holes and mordanting the copper surfaces, are performed in a single step. The treatment for conditioning the walls of the through holes is performed by means of non-surfactant, water soluble polymers belonging to the group of the cationic polyelectrolytes.

Abstract: An aqueous solution for electroless autocatalytic copper plating, containing a source of cupric ions, a source of hydroxylic ions, a reducing agent and a complexing agent in such a quantity as to render soluble the cupric ions in an alkaline medium, which further contains a stabilizing mixture formed by allylthiourea, at least a ferrocyanide of alkali metal or of ammonium ion, and at least an octylphenylether of ethylene polyoxide with 9-10 moles of ethylene oxide for each mole of octylphenol, the said three stabilizing compounds exerting a synergical action.This solution shows a very good stability and produces copper deposits having clear and brilliant appearance and good ductility properties.

Abstract: The invention relates to a chemical solution capable of selectively stripping a layer of tin or tin-lead alloy from a substrate, generally of copper, by means of a spraying operation, without requiring the use of any specially designed machine, inasmuch as the solution does not exhibit any particular aggressiveness in respect of the metal materials of which the spraying machines are usually made, and is nevertheless able to selectively strip and maintain in solution the tin or the tin-lead alloy, without etching the copper substrate. The solution comprises mainly an acid of organic nature appertaining to the group including the class of the alkylsulfonic acids having a number of carbon atoms from 1 to 4, such as in particular the methanesulfonic acid. The solution also contains an aromatic nitro-substituted compound including a solubilizing group, which is adapted to oxidize the tin-lead alloy and to facilitate the etching action of the organic acid.

Abstract: The electroless deposition of nickel base alloys is improved by incorporating in the bath ions of vanadium and of at least one of the metals thallium, vanadium, tin, zinc or tungsten. Three of these metals give even better results, and best results are obtained with four or all five. The effect of the plural added metals is synergetic, to improve corrosion resistance, freedom from porosity, and brightness of the deposited coating.

Abstract: A silver base activating solution, for use prior to electroless copper deposition, contains a salt of a weak oxyacid of an element of group III, IV, V or VI of the periodic system, e.g. sodium tetraborate. A relatively low silver concentration, within the range of 0.01 g/l to 1 g/l can accordingly be used; and the resulting copper coating forms quickly and is compact, smooth and adherent. The silver solution is stable.