Bruce M Eliash

53243994, Jun 28, 1994

May 12, 1992

7/881586

Frank A. Ludwig - Rancho Palos Verdes CA
Bruce M. Eliash - Los Angeles CA

Hughes Aircraft Company - Los Angeles CA

G01N 2726

2041531

A method and system for monitoring the quality of a phosphate coating on a metal surface having a large surface area. The method comprises applying a current or potential between the metal surface and one or more counter electrodes while they are in the phosphating solution and superimposing a constant ac signal thereon. An ac impedance spectra is obtained by measuring the ac potential between the metal substrate and one or more reference electrodes located between the counter electrode and the substrate. The ac impedance spectra provide an indication of defects in the phosphate coating even when the defects are located within a relatively small region of the total surface area of the metal surface.

54706696, Nov 28, 1995

Mar 27, 1989

7/336457

Frank A. Ludwig - Rancho Palos Verdes CA
Carl W. Townsend - Los Angeles CA
Bruce M. Eliash - Los Angeles CA

Hughes Aircraft Company - Los Angeles CA

H01M 814
H01M 818
C25D 1700

429 17

A thermal electrochemical system in which an electrical current is generated between a cathode immersed in a concentrated aqueous solution of phosphoric acid and an anode immersed in a molten salt solution of ammonium phosphate and monohydric ammonium phosphate. Reactants consumed at the electrodes during the electrochemical reaction are thermochemically regenerated and recycled to the electrodes to provide continuous operation of the system.

52981312, Mar 29, 1994

May 28, 1993

8/068030

Bruce M. Eliash - Los Angeles CA
Frank A. Ludwig - Rancho Palos Verdes CA
Nguyet H. Phan - Los Angeles CA
Vilambi N. Reddy - Jamaica NY

Hughes Aircraft Company - Los Angeles CA

G01N 2726

2041531

A method of monitoring in-tank and on-line metal ion content within a plating bath. The method involves the steps of applying a pretreatment signal to a sensing electrode positioned within the plating bath, applying a sweep signal to the pretreated sensing electrode, and measuring the voltammetric peak current of the resultant response signal. The voltammetric peak current is proportional to the metal ion content of the plating bath. The method complements and is easily integrated with known voltammetric techniques for analysis of trace and major constituents, and is thus an integral part of an efficient overall plating bath analysis system.

52870600, Feb 15, 1994

Nov 17, 1992

7/977389

Vilambi N. Reddy - Lakewood CA
Bruce M. Eliash - Los Angeles CA
Frank A. Ludwig - Rancho Palos Verdes CA
Nguyet H. Phan - Los Angeles CA

Hughes Aircraft Company - Los Angeles CA

G01N 3318

324439

A conductivity sensor adapted for use in the conductimetric analysis of liquids includes a pair of conductivity electrodes incorporated into a conductivity cell assembly having a liquid flow control chamber, sensing chamber, and liquid exit chamber. Liquids to be measured are pumped into the liquid flow control chamber, where any turbulence in the liquid is dampened. The non-turbulent liquid is passed from the liquid flow control chamber to the sensing chamber, where the conductivity of the liquid is determined. The sensing chamber is adapted for changing the height of a column of liquid between the pair of conductivity electrodes in order to vary the cell constant of the sensor. The non-turbulent liquid is passed from the sensing chamber to the liquid exit chamber, where it exits the sensor. The sensor is well-suited for use in measuring conductivities of plating bath solutions and monitoring concentrations of major constituents of plating bath solutions.

52961249, Mar 22, 1994

Nov 10, 1992

7/974650

Bruce M. Eliash - Los Angeles CA
Vilambi N. R. K. Reddy - Lakewood CA
Frank A. Ludwig - Rancho Palos Verdes CA
Nguyet H. Phan - Los Angeles CA

Hughes Aircraft Company - Los Angeles CA

G01N 2726

204402

A method of forming a reference electrode having a continuously stable reference voltage and particularly well-suited for use in an in-tank electrochemical sensor. The method utilizes an inert substrate and a counter electrode, both immersed in electroplating fluid. Current is passed between the inert substrate and the counter electrode to strip and subsequently replate the inert substrate, which then serves as the reference electrode. The steps of stripping and replating the reference electrode are periodically repeated to maintain the stability of the reference electrode voltage.

53207246, Jun 14, 1994

Nov 17, 1992

7/977344

Frank A. Ludwig - Rancho Palos Verdes CA
Bruce M. Eliash - Los Angeles CA
Nguyet H. Phan - Los Angeles CA
Vilambi N. R. K. Reddy - Lakewood CA

Hughes Aircraft Company - Los Angeles CA

G01N 2726

2041531

A method of monitoring a plating bath which combines ac and dc voltammetry to accurately measure major and trace constituent concentrations. The method involves applying both ac and dc voltammetric signals to a pretreated electrode in contact with the plating bath solution, measuring the ac and dc response current spectra, and comparing the resultant spectra to determine which provides maximum spectral detail for monitoring particular constituents with minimum interference from other constituents. Then, the ac and dc response current spectra are each used to monitor the particular constituents for which each provides the best accuracy. The method complements and is easily integrated with known voltammetric techniques and equipment.

53244001, Jun 28, 1994

Dec 4, 1992

7/986846

Bruce M. Eliash - Los Angeles CA
Nguyet H. Phan - Los Angeles CA
Frank A. Ludwig - Rancho Palos Verdes CA
Vilambi N. Reddy - Lakewood CA

Hughes Aircraft Company - Los Angeles CA

G01N 2726

2041531

A method of preconditioning an electrode for use in a plating bath monitoring process. The method involves applying at least one anodic signal to an electrode in contact with the plating bath solution in order to yield a reproducibly clean and stabilized electrode surface, and then applying a plating signal to deposit a layer of metal on the anodically treated electrode. The resultant preconditioned electrode improves the accuracy and precision of subsequent voltammetric monitoring measurements for a variety of different plating baths. The method is easily integrated with and thereby enhances the capabilities of known voltammetric plating bath monitoring processes.

52981320, Mar 29, 1994

Mar 25, 1993

8/037159

Vilambi N. R. K. Reddy - Lakewood CA
Bruce M. Eliash - Los Angeles CA
Frank A. Ludwig - Rancho Palos Verdes CA
Nguyet H. Phan - Los Angeles CA

Hughes Aircraft Company - Los Angeles CA

G01N 2726

2041531

A method for monitoring the status of a plating bath purification treatment cycle. The method involves applying a swept dc measurement signal to a pretreated electrode which is in contact with the plating solution, and monitoring the resultant response current signal. The electrode potential corresponding to the peak current density in the cathodic sweep of the response current signal provides an accurate indication of the status of the purification treatment cycle. The method tracks the progress of the purification process thereby ensuring the optimal termination points for the treatment process. The method can be used in conjunction with voltammetric plating bath analysis methods and equipment, as part of an overall plating bath monitoring and control system.