At+t Corp.

Lucent Technologies Inc.

At&t Bell Laboratories

Atlantic Richfield Company

Halcon Research and Development Corp.

Sudarshan Lal

Donald Dinella

Craig G Smith

Richard V Porcelli

David A Nicol

Yutaka Okinaka

Kim L Morton

Chwan-Tsann Wang

Alfred J Grady, Jr

Eugene P Foeckler, Jr

Harvey S Trop

Mary J Mitchell

Proposed is a technique for determining the suitability of use of a material for an electroless plating operation. A solution including the material is subject to an anodic linear sweep voltammetric measurement. The resulting anodic peak is compared with that of a control solution in order to evaluate the potential of the material for poisoning a factory plating bath.

Method for testing materials for use in electroless plating

A method for treating the waste stream resulting from electroless plating operations such as copper electroless plating. The waste stream is simultaneously treated with hydrogen peroxide and UV light to bring the level of contaminants below the discharge limit. In one embodiment, the waste stream is also diluted with rinse water from the plating process.

Treatment of electroless plating waste streams

Disclosed is a method for testing solder mask material for suitability with an electroless plating process. The Emix potential of the electroless bath is measured. A test substrate including the mask material is then immersed in an electrolyte, and a constant potential at least equal to the Emix potential is applied to a pair of electrodes also immersed in the electrolyte. The test substrate is then inspected to determine adherence of the mask material.

Method for testing solder mask material

Disclosed is a method for removal of contaminants and replenishment of an electroless copper plating solution in order to allow reuse of the solution. Copper oxide is dissolved in the spent solution and this is followed by an electrodialysis which removes formate and carbonate ions.

Regeneration of spent electroless copper plating solution

Disclosed is a method of monitoring electroless plating solutions. The solutions are used to plate a light-transmitting medium. Measurements are made to determine the time it takes for light transmission through the medium to be reduced to a certain level. This measurement can be used to determine whether articles will be sufficiently plated by the solutions.

Monitoring electroless plating baths

This invention is a process for etching copper sheets on insulating boards for use in fabricating multilayer printed circuit boards. The improvement resides in adding to a standard copper etching solution certain alkyltrimethyl ammonium chlorides with alkyl chain lengths ranging from 6 to 20 carbon atoms in amounts sufficient to yield intermediate kinetics behavior. Of special interest are dodecyltrimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride and octadecyltrimethyl ammonium chloride present in an amount of from 0.01 to 1.0 wt %. A silicon-based antiforming agent may be added in amounts of from 0.05 to 2.0 wt. % to prevent an unacceptably large amount of foam from occurring during etching. With this formulation, the rate is mass transport controlled at low rates and almost independent of mass transport at high rates due to the inhibition of the surface reaction rate. As a result, non-uniformities in etch rates due to variations in mass transport conditions in processing equipment may be eliminated. This unique formulation could significantly improve the yields presently obtained in manufacturing as well as allow the processing of fine-line multilayer circuit boards.

Uniformity of copper etching in the fabrication of multilayer printed

A process is provided for inhibiting the rate of corrosion of titanium metal surfaces from attack by strong acid media in which at least a portion of the titanium metal surface is coated with rhodium metal to provide a treated metal surface which is substantially impervious to corrosion by strong acid media. The article so prepared appears to be uniquely impervious to corrosion by strong acid media and is also claimed herein.

Growing community of inventors

Glen Rock, NJ, United States of America

Sudarshan Lal