BRIGHT ACID COPPER UNICOPPER AC 380
PHYSICAL PROPERTIES:
UNICOPPER AC 381: Clear colourless Liquid.
UNICOPPER AC 382: Yellowish Liquid.
DESCRIPTION:
The UNICOPPER AC 380 process produces extremely bright copper deposits from
an acid sulphate bath. It shows excellent levelling, coupled with good throwing power.
Copper deposits obtained from UNICOPPER AC 380 are ductile, give good
corrosion resistance and exhibit no pitting.
UNICOPPER AC 380 process is easy to operate and can be used over steel, zinc diecastings, after required pre-treatment(see below), and in "plating on Plastics". It is very
economical to operate due to its low operating temperature, its versatility and its
simple effluent treatment.
UNICOPPER 380 contains no colour dye.
EQUIPMENT:
Tanks and filtration
Tanks should be rubber lined steel tanks or other suitable plastic tanks. Tanks should
be equipped with mechanical agitation or air lines. Air must be free of oil.
Continuous filtration is a pre-requisite for successful plating. The back wash type filter
is recommended for this operation. Heating and cooling facilities should also be
available.
Anodes
The UNICOPPER AC 380 Process requires copper anodes with a phosphorous
content of 0.02 - 0.06%. Cast anodes are generally used but sheets, granules or chips
are also suitable. The latter are used in connection with titanium baskets. Before
copper anodes are placed in the tank they should be cleaned and any mill coating
should have been removed by way of sand blasting. Soon after copper anodes have
been placed in operation, hey should be covered with a dark to black coating. This
indicated that they are working properly. If so desirable, anode bags can be used. The
recommended material is polypropylene.
OPERATING DATA:
MAKE-UP
Copper Sulphate x 5H O
²
Sulphuric Acid Conc. c.p.
Chloride tolerance
H.Donsbach
Rev 1.1
RANGE
OPTIMUM
180 - 220 g/l
60 - 90 g/l
70 - 300 mg/l
200 g/l
70 g/l
150 mg/l
08.11.2002
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UNICOPPER AC 381
Brightener
UNICOPPER AC 382
Basic Brightener
1 - 3 ml/l
2 ml/l
3 - 6 ml/l
4 ml/l
WORKING CONDITIONS:
Cathode Current Density
1,0 - 6 A/dm²
Anode Current Density
0,5 - 2,5 A/dm²
Voltage
1,5 - 6 Volts
Current Efficiency
approx. 100%
Temperature
20 - 50° C
MAKE UP OF A UNICOPPER AC 380 ACID COPPER SOLUTION:
Dissolve required amount of copper sulphate in hot de-mineralised water. This water
should not contain more than 300 mg Cl- /liter. Start continuous filtration with small
amounts of activated carbon, washed onto the filter. Slowly, add the required amount
of Sulphuric Acid to the solution and fill up the desired level with water. Cool to
operating temperature, remove activated carbon from the filter and add required
amounts of UNICOPPER AC - 380 addition agents. Dummying for approximately
two hours at 0.5 A/dm² will remove any trace amounts of foreign metals.
PRE-AND POST-TREATMENT OF PARTS:
Steel Parts
Parts to be plated should be thoroughly cleaned in a soak cleaner, followed by an
electrolytic cleaner, acid dip, copper or nickel strike, and acid dip. Water rinses are
placed between each step.
Zinc Die-Castings
Cleaning cycle same as above. Copper strike or alkaline Nickel to a thickness of
3 - 5 microns.
H.Donsbach
Rev 1.1
08.11.2002
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CONSUMPTION OF UNICOPPER AC 380 ADDITION AGENTS
per 10.000 Ah at normal operation
800 – 1200 ml
500 – 800 ml
UNICOPPER AC 381 Brightener
UNICOPPER AC 382 Basic Brightener
If there is no improvement-effect of the quality by adding the additives, please
check Chloride content.
GENERAL INFORMATION:
Proper racking of parts is of utmost importance. Care should be taken that parts do not
shade each other.
From time to time steel or zinc die-cast parts may fall into the plating solution. We
recommend to remove these parts immediately, so that they will not contaminate the
plating solution.
Temperature
Though the UNICOPPER AC 380 process is very tolerant to temperature, it is
advisable to stay within specified limits. High temperatures will reduce overall
brightness and increase brightener consumption. Low temperatures may cause anode
polarisation, burning in high current density areas.
Copper Content
Copper content of the plating solution should be determined weekly and should be
kept within the recommended range. If the metal content of the bath drops rapidly
without apparent reason, anode area should be increased. This can be done by hanging
extra copper anodes into the plating solution.
Sulphuric Acid Content
A sulphuric acid determination should be run in connection with the weekly copper
analysis. Sulphuric acid should not go above 80 g/l since this would reduce the copper
metal solubility in the solution.
Chloride Content
Chloride content must be kept within the specified limits. An excess of chloride will
reduce the levelling properties of the UNICOPPER AC 380 process. Lack of chloride
will reduce the degree of brightness.
H.Donsbach
Rev 1.1
08.11.2002
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Correction:
Lack of chloride: 2,5 ml chemically pure Hydrochloric Acid contains 1 g of chlorid
ions.
Excess of chloride: 4,5 g silver sulphate will precipitate 1 g of chloride ions.
Addition Agents
Addition agents should be added according to the ampere-hours plated. It is, however,
recommended to check the content of addition agents in a Hull Cell plating test. This
is done by plating a brass panel at 2 Amperes for 10 minutes in the copper solution to
be tested.
This panel is then compared to a standard panel, which was plated in a copper bath at
optimum conditions. Using the information contained under hereunder, it should be
easy to determine which addition agent is lacking or in excess.
Addition agents must be kept in a dry place, at room temperature (18 - 30°C) to avoid
their crystallisation or evaporation.
REMOVAL OF CONTAMINATION:
Activated Carbon
From time to time it is recommended to make an activated carbon treatment in order to
remove organic contaminations caused by drag-in or de-composition of addition
agents.
Activated carbon is added at a rate of 0,5 to 2,0 kg per 100 l plating solution,
depending on the degree of contamination.
Activated carbon is added to the solution in a separate tank, stirred for two hours,
allowed to settle and filtered back into the plating tank.
It is important that no carbon is carried over into the plating tank, since this can lead to
rough deposits.
SAFETY PRECAUTIONS:
see Material Safety Data Sheet
GUARANTEE:
Above instructions and recommendations are the result of intensive testing and shop
experiences. They are for your information, only.
Our guarantee extends to the continuous quality of our products as they leave our
factory and not to their usage in the field, which is a factor beyond the control of a
supplier.
H.Donsbach
Rev 1.1
08.11.2002
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