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Showing papers on "Electroless nickel plating published in 1968"


Patent
23 Sep 1968
TL;DR: HIGH STABILITY, AUTOCATALYTIC ELECTROLESS NICKEL PLATING BATH COMPRISING an AQUEOUS SOLUTION CONTAINing about 0.08-016 MOLE/LITER NICKels IONS, about 019-0.38 MOLE / LITER HYPOPHOSPHITE IONS and ESSENTIALLY about 035-3.14 MOLE or Liter CITRATE IONS as discussed by the authors.
Abstract: HIGH STABILITY, AUTOCATALYTIC ELECTROLESS NICKEL PLATING BATH COMPRISING AN AQUEOUS SOLUTION CONTAINING ABOUT 0.08-016 MOLE/LITER NICKEL IONS, ABOUT 0.19-0.38 MOLE/ LITER HYPOPHOSPHITE IONS, AND ESSENTIALLY ABOUT 0.35-3.68 MOLE/LITER AMMONIUM IONS, ABOUT 0.0.-1.07 MOLE/LITER ACETATE ION AND ABOUT 0.007-0.14 MOLE/LITER CITRATE IONS, THE SOLUTION HAVING A PH IN THE RANGE OF ABOUT 7.0 TO ABOUT 9.5 THE AMMONIUM IONS COMPLEX PALLADOUS IONS INTRODUCED INTO THE PLATING BATH BY "DRAG OUT" FROM THE ACTIVATOR SOLUTION TO FORM A SOLUBLE AMMONIUM-PALLADIUM COMPLEX, WHICH INHIBITS REDUCTION OF PALLADOUS ION TO ZERO VALENT CATALYTIC PALLADIUM BY THE HYPOPHOSPHITE OF THE BATH. BY THE REMOVAL OF POTENTIAL CATALYST SITES FROM THE BATH OR BY RENDERING THE POTENTIAL SITES RELATIVELY CATALYTICALLY INACTIVE, RANDOM DEPOSITION OF THE NICKEL AND PREMATURE LOSS OF THE BATH IS AVOIDED.

154 citations


Journal ArticleDOI
TL;DR: In this article, an electroless Ni plating of Si wafers with p-n junctions using conventional solutions was performed and a pronounced difference in plating rate between p and n-type surfaces was observed.
Abstract: In the study of electroless Ni plating of Si wafers with p‐n junctions using conventional solutions, a pronounced difference in plating rate between p‐ and n‐type surfaces is observed. Further experiments show that rate difference probably should not only be attributed to the photovoltaic effect generated at the p‐n junctions but also to the electronegativity difference between p‐ and n‐type Si. The latter effect can be changed by addition of such material as or to the plating solution. Whereas addition increases the rate difference, EDTA addition decreases it. This fact which can be put to practical use gives an extra support for the explanation given above.

35 citations


Patent
13 Dec 1968
TL;DR: A SILICON SURFACE is prepared for ELECTROLESS NICKEL PLATING by ACTIVATION with an AQUEOUS HYDROFLUORIC ACID Solution CONTAINING from 1 E to 1 HUNDRED P.M. of Ionic gold as mentioned in this paper.
Abstract: A SILICON SURFACE IS PREPARED FOR ELECTROLESS NICKEL PLATING BY ACTIVATION WITH AN AQUEOUS HYDROFLUORIC ACID SOLUTION CONTAINING FROM ONE E TO ONE HUNDRED P.P.M. OF IONIC GOLD. SUBSEQUENT ELECTROLESS DEPOSITION OF NICKEL PROCEEDS MORE UNIFORMLY OVER THE ENTIRE SILICON SURFACE, AND RESULTS IN A MORE STABLE, TIGHTLY ADHERING NICKEL PLATE DUE TO THE IMPROVED ACTIVATION STEP. ADDITIONAL STABILITY AND EVEN MORE RELIABLE ADHESION IS OBTAINED BY A SUBSEQUENT SINTERING OF THE COMPOSITE STRUCTURE ABOVE THE GOLD-SILICON EUTECTIC TEMPERATURE TO ALLOY THE GOLD ACTIVATION FILM WITH THE SILICON. THE SINTERING STEP ISS THEN PREFERABLY FOLLOWED BY A SECOND ELECTROLESS NICKEL PLATING STEP TO BUILD A NICKEL CONTACT AREA OF INCREASED THICKNESS.

10 citations


Journal ArticleDOI
TL;DR: In this article, the corrosion resistances of electroless nickel plating films, having different phosphorus contents from plating baths of the same compositions (but of different pH values), were measured by a few sorts of electrochemical methods and dissolution tests in solutions of IN-H2SO4, 5%-NaCl, and IN-NaOH.
Abstract: Phosphorus contents of nickel plating films obtained from electroless nickel plating baths containing various kinds of organic salts were determined.Corrosion resistances of electroless nickel plating films, having different phosphorus contents from plating baths of the same compositions (but of different pH values), were measured by a few sorts of electrochemical methods and dissolution tests in solutions of IN-H2SO4, 5%-NaCl, and IN-NaOH.As the results, the corrosion resistances of the plating films increased with the increase of phosphorus contents, but passivity effects were not found in each film containing phosphorus.

2 citations