Abstract: 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.

Abstract: Disclosed is a method of providing solder on selected portions of a printed circuit board. Solder is first electroplated over copper conductor patterns on the board by means of a first photoresist layer. After stripping the first photoresist, a second photoresist layer is laminated over the board and developed to expose selected portions of the solder. The exposed portions are selectively stripped. The copper exposed by the selective stripping is then subjected to a scrubbing while the photoresist protects the remaining solder, and the second photoresist is removed.

Abstract: A method of depositing a stress-free electroless copper deposit is disclosed. The method comprises contacting a catalyzed surface with a solution comprising a source of cupric ions; a reducing agent for the cupric ions; a complexing agent for the solution selected from (a) ethylenediaminetetraacetic acid, (b) a salt of (a), (c) a modified ethylenediamine acetic acid, (d) a salt of (c), and (e) a mixture of at least two of the foregoing complexing agents; a stabilizer for the solution comprising a mercury compound; and an accelerator for the solution comprising a water-soluble compound containing a cyanide radical (CN.sup.-) complexed with a metal selected from Group VIII of the Periodic Table of the Elements.

Abstract: A method of depositing a metal on a surface is disclosed. The method comprises coating the surface with a sensitizing solution comprising at least a reducible salt of a non-noble metal. The coated surface is selectively treated to reduce the metal salt to metallic nuclei to form a catalytic pattern thereon capable of directly catalyzing the deposition of a metal on the nuclei from an electroless metal deposition solution. The selectively treated surface is then exposed to a stripping solution comprising an organic acid selected from (a) a carboxylic acid having a structural formula of ##STR1## where R is a member selected from the hydrogen radical, H, and an alkyl group having 1 to 3 carbon atoms, (b) citric acid and (c) a mixture of any of the foregoing acids, to essentially remove portions of the coated surface which have not been selectively treated.

Abstract: A method of depositing a stress-free electroless copper deposit is disclosed. The method comprises contacting a catalyzed surface with a solution comprising a source of cupric ions; a reducing agent for the cupric ions; a complexing agent for the solution selected from (a) ethylenediaminetetraacetic acid, (b) a salt of (a), (c) a modified ethylenediamine acetic acid, (d) a salt of (c), and (e) a mixture of at least two of the foregoing complexing agents; a stabilizer for the solution comprising a mercury compound; and an accelerator for the solution comprising a water-soluble compound containing a cyanide radical (CN.sup.-) complexed with a metal selected from Group VIII of the Periodic Table of the Elements.