To make a bright electroless plating can do by simple technique to process by immersion technique. Deposit metal can cover onto copper, brass, copper based alloy, gold and lead tin electroplate.
Description:
The process is based on the reduction characteristics of chelated tin in divalent state. Under certain condition, reduction process to pure tin occur readily. On this process use grain-refining agent, free of phosporus, is present as well as an activator and buffer for pH control. Bright electroless plating can use to provide corrosion protection to copper and lead tin electroplate, minimum plate thick about 25 millionths of an inch of tin deposit required.
Bright Electroless Tin is recommended to preserve solderability of printed boards, either copper or lead-tin electroplate. This is also use for plating electronic parts such as diodes or leads and for corrosion protection of die stampings and machined copper or brass parts.
Formula Use:
Prepare electroless plating solution use 5 lbs Tin Powder with one half gallon water and add 4 gallons water. Mix all material will dissolved at about 180 oF.
Yield:
Bright electroless Tin will deposit about 25 millionths of an inch over 100 sq ft of copper/gallon of plating solution.
Showing posts with label Bright Plating. Show all posts
Showing posts with label Bright Plating. Show all posts
Sunday, October 7, 2012
Wednesday, June 25, 2008
Brightening Agents
Find Brightening Agents:
Thiourea additions brighten copper deposited from acid sulfate baths. A patent disclosed the use of 0.002 to 0.005 g/l. An appreciable grain-refining and brightening effects of thiourea are attributed to its adsorption in copper deposits and the resulting effect on crystal nucleation.
Sulfide ions created when thiourea decomposeds reduce the ductility of copper deposits. Combined with dextrin, molasses, lignosulfonats, mercaptobenzimdazoles, naphthalene sulfonic acid, or tribenzylamine and other organic agents, small concentrations of thiourea were once employed for brightening purposes, but have been largely superseded by better brighteners that have little or no harmful effect on ductility.
Sulfonated acetylthiourea or sulfanated aryl and alkyl substitution products of acetylthiourea were developed for bright copper plating from acid baths. Another process utilized the sulfonation products of sulfurized aromatic compounds presence of anhydrous aluminum chloride or thionyl chloride in the presence of anhydrous aluminum chloride and sulfuric acid. Acetyl cyanide was proposed as a brightener for either the sulfate or the floroborate bath. Several complex amines was patented as brightening agents in 1958. In 1958, a patent disclosed a combination of thiohydantion (a thiourea derivative) and a multiringed aromatic amine. A substituted amino benzene sulfonic acid was disclosed in another patent for brightening copper deposited from the copper sulfate bath.
Polyacrylamides, the reaction product of aminothiazole, acrylaminates, thiocarboxylic acid amides, tetrahydropyranyl amides, homopolymers of 1-3-dioxolane, and a combination of phenol polyglycols and thiosemicarbozones are also included among the brightening agents patented since 1955.
Some of these brightening agents also induce leveling. For example, a surface finish of 0.46 μm with 12.5 μm of good leveling bright copper or to only 0.1 μm with 25 μm. Such processes deposit copper with a leveling power much higher than typical bright nickel deposits.
Thiourea additions brighten copper deposited from acid sulfate baths. A patent disclosed the use of 0.002 to 0.005 g/l. An appreciable grain-refining and brightening effects of thiourea are attributed to its adsorption in copper deposits and the resulting effect on crystal nucleation.
Sulfide ions created when thiourea decomposeds reduce the ductility of copper deposits. Combined with dextrin, molasses, lignosulfonats, mercaptobenzimdazoles, naphthalene sulfonic acid, or tribenzylamine and other organic agents, small concentrations of thiourea were once employed for brightening purposes, but have been largely superseded by better brighteners that have little or no harmful effect on ductility.
Sulfonated acetylthiourea or sulfanated aryl and alkyl substitution products of acetylthiourea were developed for bright copper plating from acid baths. Another process utilized the sulfonation products of sulfurized aromatic compounds presence of anhydrous aluminum chloride or thionyl chloride in the presence of anhydrous aluminum chloride and sulfuric acid. Acetyl cyanide was proposed as a brightener for either the sulfate or the floroborate bath. Several complex amines was patented as brightening agents in 1958. In 1958, a patent disclosed a combination of thiohydantion (a thiourea derivative) and a multiringed aromatic amine. A substituted amino benzene sulfonic acid was disclosed in another patent for brightening copper deposited from the copper sulfate bath.
Polyacrylamides, the reaction product of aminothiazole, acrylaminates, thiocarboxylic acid amides, tetrahydropyranyl amides, homopolymers of 1-3-dioxolane, and a combination of phenol polyglycols and thiosemicarbozones are also included among the brightening agents patented since 1955.
Some of these brightening agents also induce leveling. For example, a surface finish of 0.46 μm with 12.5 μm of good leveling bright copper or to only 0.1 μm with 25 μm. Such processes deposit copper with a leveling power much higher than typical bright nickel deposits.
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