Abstract: A surface treatment method of cladding a Sn or Sn alloy coating with one or more metals selected from among Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Ga, In, Ti, Ge, Pb, Sb and Bi continuously or discontinuously in such a way as to make the Sn or Sn alloy coating partially exposed, which method makes it possible to inhibit the generation of whiskers in an Sn or Sn alloy coating formed on the surface of a substrate to which other member is pressure-welded or the joint surface to be soldered. Cladding an Sn or Sn alloy coating with a prescribed metal continuously or discontinuously in such a way as to make the coating partially exposed inhibits the generation of whiskers by contact pressure in pressure welding, and further inhibits the generation of whiskers without impairing the solder wettability of the coating even when the cladding is not followed by heat treatment or reflowing.

Abstract: Disclosed is a tin electroplating bath containing a water-soluble tin salt, one or more substances selected from inorganic acids, organic acids and their water-soluble salts, and one or more substances selected from water-soluble tungsten salts, water-soluble molybdenum salts and water-soluble manganese salts. This tin electroplating bath enables to form a tin-plated coating film on components for electronic devices such as a chip component, crystal oscillator, bump, connector, lead frame, hoop member, semiconductor package and printed board, as a substitute for a tin-lead alloy plating material, while having high whisker suppressing effects.

Abstract: A surface treatment method of cladding a Sn or Sn alloy coating with one or more metals selected from among Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Ga, In, Ti, Ge, Pb, Sb and Bi continuously or discontinuously in such a way as to make the Sn or Sn alloy coating partially exposed, which method makes it possible to inhibit the generation of whiskers in an Sn or Sn alloy coating formed on the surface of a substrate to which other member is pressure-welded or the joint surface to be soldered. Cladding an Sn or Sn alloy coating with a prescribed metal continuously or discontinuously in such a way as to make the coating partially exposed inhibits the generation of whiskers by contact pressure in pressure welding, and further inhibits the generation of whiskers without impairing the solder wettability of the coating even when the cladding is not followed by heat treatment or reflowing.

Abstract: Disclosed is a tin electroplating bath containing a water-soluble tin salt, one or more substances selected from inorganic acids, organic acids and their water-soluble salts, and one or more substances selected from water-soluble tungsten salts, water-soluble molybdenum salts and water-soluble manganese salts. This tin electroplating bath enables to form a tin-plated coating film on components for electronic devices such as a chip component, crystal oscillator, bump, connector, lead frame, hoop member, semiconductor package and printed board, as a substitute for a tin-lead alloy plating material, while having high whisker suppressing effects.

Abstract: A tin-copper alloy electroplating bath which comprises a water-soluble tin salt, a water-soluble copper salt, an inorganic or organic acid or a water-soluble salt thereof, and one or more compounds selected from thioamide compounds and thiol compounds. The present invention makes it possible to form a tin-copper alloy deposit, in place of tin-lead alloy plating, on electronic parts such as chips, quartz crystal oscillators, hoops, connector pins, lead frames, bumps, lead pins of packages, and printed circuit boards.

Abstract: A tin-copper alloy electroplating bath which comprises a water-soluble tin salt, a water-soluble copper salt, an inorganic or organic acid or a water-soluble salt thereof, and one or more compounds selected from thioamide compounds and thiol compounds. The present invention makes it possible to form a tin-copper alloy deposit, in place of tin-lead alloy plating, on electronic parts such as chips, quartz crystal oscillators, hoops, connector pins, lead frames, bumps, lead pins of packages, and printed circuit boards.

Abstract: Disclosed is a tin-silver alloy electroplating bath containing: (A) stannous salt; (B) silver salt; (C) one kind or two or more kinds of acids selected from the group consisting of sulfuric acid, phosphoric acid, phosphonic acid, hydroxycarboxylic acid, alkanesulfonic acid, and alkanolsulfonic acid; (D) thiourea; (E) nonionic surface active agent; and (F) one kind or two or more kinds of additives selected from the group consisting of a mercapto group containing aromatic compound, dioxyaromatic compound, and unsaturated carboxylic acid. The electroplating using the above electroplating bath is allowed to form a homogeneous tin-silver alloy plated film having a good external appearance by eliminating preferential deposition of silver and substitutional deposition of silver on an anode and the plated film.

Abstract: To an electroless gold plating bath comprising a water-soluble gold compound, a complexing agent, and a reducing agent is added a small amount of polyvinyl pyrrodidone. The bath allows a satisfactory gold plating film to be formed on metal portions on a non-conductive substrate without plating spread.

Abstract: A bath for electrodepositing tin, lead or an alloy thereof, containing a tin and/or lead ion and a sulfate ion becomes stable at pH 1 or higher when a condensed phosphate ion is added thereto. The bath is effective for depositing tin-lead alloy films on sealing glass-metal integrated articles.