Canadian Finishing & Coatings Manufacturing September/October Issue - 35

PLATING AND ANODIZING: COMPONENT FINISHING ALTERNATIVE
applications, especially for connector
applications. Tests demonstrate that the
bright silver deposit can meet industrial
requests regarding ductility.
Adhesion
In most applications, silver is electroplated
over either copper and copper alloys, or
nickel undercoats. To ensure good adhesion
of silver over nickel undercoats, a thin silver
strike layer is necessary prior to silver
plating. For plating over nickel substrates,
GT-101 Silver Strike, is employed.
Purity
Silver deposit purity is important to many
end users. Unlike most cyanide-based silver
electrolytes, the cyanide-free electrolyte
does not contain any metallic brightening
agents. Any impurities are mainly
associated with co-deposited carbon
originating from the organic additives used
in the electrolyte. Tests confirm > 99.9 per
cent silver purity in deposits from GT-101
Bright Silver.
Corrosion and tarnish resistance
An accelerated tarnish test shows that the
tarnish tendency of silver from SILVERON
GT-101 Silver is comparable to that of
deposits from a conventional cyanidebased
electrolyte. Several commercially
available Cr6+- free, organic, and inorganic
anti-tarnish agents have been found to
prevent tarnishing of the SILVERON GT101
silver deposit, even under severe test
conditions.
Contact resistance
Electroplated silver is an excellent contact
material and has been widely used for
electrical and electronic connector
applications, where low contact resistance
of the silver deposit is essential. A very
low contact resistance (below 1 mOhm)
can be achieved when contact loading is
above 40 cN. This result is comparable
to that obtained on silver deposits from
conventional cyanide silver.
Solderability
Solder wetting performance is another
important parameter. Tests performed
using a wetting balance technique showed
that none of the aging conditions tested
(deposition on copper, dry heat
aging,
steam aging) have any significant impact
on the solderability of the silver. Zerocrossing
time (ZCT) observed at all testing
conditions was well below one second,
indicating that the new silver deposit has
excellent solderability.
Wire bonding capability
In wire bonding applications, several
different types of silver finishes provide
QAS INTERNATIONAL
ISO 9001:2015
REGISTERED COMPANY
Certificate No. CAN1641
91 Esna Park Drive, Unit #7
Markham, Ontario L3R 2S2
Phone: (905) 477-0900
www.dynamix-inc.com
September/October 2022
35
protection of copper substrates and allow formation of a strong bond between gold wire
and silver-plated substrates. Several gold wire bonding and pull tests performed on wire
bonding samples (prepared by plating GT-101 directly over a copper substrate) confirm
that cyanide-free silver can provide a good wire-bondable surface.
David Wayness is the finishing marketing leader for the DuPont Electronics and Industrial
business.
For the full feature, visit www.cfcm.ca
DYNAMIX Blending Technology, Service and Value
DYNASTRIP RT
Room TemperaturePaint Stripper
Alkaline material designed to strip off a variety of paints
from steel, stainless steel, aluminum, galvanized steel,
copper and brass or other sensitive surfaces.
* Operates at room temperature.
* Environmentally friendly product.
* 100 % biodegradable product.
* Stripping ability equal to hot paint strippers.
* Excellent replacement for strippers containing
chlorinated solvents such as methylene chloride.
* Breaks the chemical bond of paint molecules.
PRETREATMENT SOLUTIONS
For Metal Preparation Before Powder or
Wet Coatings and Finishing.
* General purpose and heavy-duty cleaners for all substrates and applications.
* Iron, Zinc, Manganese phosphates and topcoats.
* Environmentally friendly chrome-free pretreatments.
* Aluminum cleaners and deoxidizers.
* RoHS compliant coatings.
Contact us for Information on:
* Anodizing * Black Oxide and Antiquing * Conversion Coatings
* Corrosion Preventatives/ Topcoats * Electroless Nickel Plating Processes
* Electroplating Processes * Electropolishing * Phosphating * Pretreatment / Cleaners
* Metal and Paint Strippers * Waste Treatment * Commodities.
http://www.cfcm.ca http://www.dynamix-inc.com
Canadian Finishing & Coatings Manufacturing September/October Issue

Table of Contents for the Digital Edition of Canadian Finishing & Coatings Manufacturing September/October Issue
