摘要:
A tin-lead alloy plating bath based on a principal plating bath comprising an alkanesulfonic or alkanolsulfonic acid and both bivalent tin and lead salts thereof is characterized by the addition of a guanamine compound having the general formula
wherein R, and R 2 , which may be the same or different, present each a hydrogen atom, C 1-18 straight- or branched-chain alkyl radical, C 1-18 straight- or branched-chain alkoxy-lower alkyl radical, or a C 3-7 cycloalkyl radical, or R 1 and R 2 may combine to form a carbon cycle or hetero cycle, and A represents a lower alkylene radical.
摘要:
A bismuth or bismuth alloy plating bath comprises as essential ingredients an organic sulfonic acid of the general formula (I) wherein R is a C 1 - 5 alkyl radical, X 1 is a halogen atom or hydroxyl, aryl, alkylaryl, carboxyl, or sulfonyl radical which may be in any optional position of the alkyl radical, and n is an integer of 0 to 3, or of the formula (II) wherein X 2 is a halogen atom or hydroxyl, alkyl, aryl, alkylaryl, aldehyde, carboxyl, nitro, mercapto, sulfonyl, or amino radical, or two X 2 ' S which may combine with a benzene ring to form a naphthalene ring, and m is an integer of 0 to 3, and a bismuth salt of the acid or a mixture of the bismuth salt of the acid and one or more other metal salts of the acid.
摘要:
A tin, lead, or tin-lead alloy plating bath comprising, as essential ingredients, an alkali metal salt, and a soluble divalent tin compound or/and a lead compound, all of an aliphatic or aromatic sulfocarboxylic acid of the general formula wherein R is a C 1-4 hydrocarbon radical, M 1 is a hydrogen atom or alkali metal atom, M 2 is an alkali metal atom, and X 1 and X 2 are each a hydrogen atom, OH, COON, or SO 3 N (where N represents a hydrogen atom or alkali metal atom).
摘要:
An electrolytic process for producing lead and tin sulfonates which comprises applying a DC voltage to an anode (2) and a plurality of cathodes (4) in an electrolytic cell and thereby dissolving lead or tin in an electrolytic solution. The electrolytic cell is partitioned by cation- and anion-exchange membranes (5,6) into anode and cathode chambers. The electrolytic solution is a solution of an organic sulfonic acid, and the anode is lead or tin. The process reduces contents of radioisotopes such as uranium and thorium to a level of less than 50 ppb, and therefore the coatings formed by solder plating using the lead and tin salts in accordance with the invention show radioactive α particle counts of less than 0.1 CPH/cm 2 .