Why Is NBP The Best?
Help! There Are So Many Finishes. How Do I Choose?
How Do I Submit A Quote?
What Finishes Do You Provide?
Check Out The Plating Finishes Page
What Is The Difference Between An Electrolytic & An Electroless Bath?
Unlike conventional electrolytic nickel, no electrical current is required for deposition of Electroless Nickel. The electroless bath provides a deposit that follows all contours of the substrate exactly, without building up at the edges and corners. A sharp edge receives the same thickness of deposit as does an internal diameter.
Why Would I Find Black Spot On Tin & Tin Lead
Fretting is a common problem with Tin Plating. This is surface damage created when there is relative motions and strong contacts between parts, usually during shipping and handling. The tin plating shows black or worn spots caused by rubbed or scratched by another part. This oxide does not effect the parts functionally. They are still solderable. A way to eliminate fretting is by changing the type of packaging. (Layer packing or plastic trays are recommended) - Metal Finishing Guidebook 1997
Are There Many Problems Associaed With Tin Plating?
There are many problems associated with tin plating. One of which is whiskering, like cadmium and zinc, thin needle-like crystals known as "whiskers" form within a period after plating that may vary from a few weeks to several years. A whisker may measure up to .0001" (2.5um) in diameter, and grow spontaneously to a length of 0.375" (10 mm). Conditions that tend to promote the growth of whiskers are compressive stresses and uniform temperatures for long periods of time. In most applications, these slender microscopic crystals would be unnoticed and harmless, but in closely spaced electronic circuits they are capable of carrying sufficient current at low voltages to cause serious short circuits or a corona discharge.
When the formation of whiskers is known to be a potential problem, the condition may be prevented by specifying that a small amount of lead be included in the tin deposit. While 1-2% lead is adequate to substantially reduce the risk of whiskering, it is customary to specify a 93% tin - 7% lead alloy to assure that the alloy remains sufficiently high in lead under all conditions of electroplating to prevent the formation of whiskers. Small quantities of antimony, copper or nickel in the tin deposit have also been reported to prevent the formation of whiskers.
What Finishes Are Good For Soldering?
The most widely used finishes for soldering are Tin, Tin/Lead & Gold.
What Precious Metals Are Used In Electroplating?
Precious metals commonly used in electroplating and surface finishing operations include gold, silver, indium, ruthenium, palladium and rhodium. Factors that influence the selection of precious metals are their contact characteristics, corrosion resistance, heat resistance, reflectivity, solderability, color and wear resistance.
Silver has an advantage of its relative low cost, but it is susceptible to tarnishing when exposed to sulfur in the atmosphere.
Gold has excellent solderability and electrical characteristics. The hardness and appearance of gold can be modified with different alloying elements.
Indium is a precious metal that has the unique quality of cold fusing at room temperature with aluminum and copper. This cold welded bond keeps out oxidation between the indium plated part and the aluminum or copper base material allowing for excellent electrical and thermal transfer contacts. This coating is the UL approved finish for connecting aluminum wiring to a copper receptacle.
What Is Electroplating?
Electroplating is a process by which metals in ionic form migrate from a positive to a negative electrode. An electrical current passing through the solution causes objects at the cathode to be coated by the metal in solution. The size, shape, and weight of the objects being plated determine how they will be plated.
Do You Have Any Black Finishes?
Check Out The Black Finishes Page
What is Passivation?
Passivation of stainless steel is not electroplating, it is a nonelectrical process whereby the free iron is chemically removed from the surface of stainless steel. This prevents the formation of possible corrosion sites and the development of tightly adhering oxides. The 300 series alloys are generally preferred for passivation, as some of the 400 series alloys will actually be discolored by the passivation process. Passivation imparts a limited neutral salt spray corrosion protection to the stainless steel, usually not much over 2 hours. It is critical when making assemblies to be passivated that all component parts be made of the same alloy; different alloys may be indistinguishable before passivation, but may have a different appearance afterward. Since different solutions are used to passivate different alloys, they must be properly identified. Mixing alloys may not only result in differences in appearance, but may result in some parts being destroyed. Passivation of stainless steel is generally specified by QQ-P-35 or ASTM A 380.
Plating on stainless steel may be done, after suitable pretreatment. Stainless steels and high-nickel alloys form a tightly adhering passive oxide film within minutes of being plated. Stainless parts can be plated with other metals if a fresh active surface is provided for subsequent plating.
Zinc Die Cast
What Does NBP's Chemical Milling Solution Do?
NBP has a proprietary chemical milling solution for cleaning zinc die cast based parts. This solution is a chemical bath and does not require electrical current. It will remove the zinc oxide layer and prepare the part for plating. It can clean out cold shut areas, remove minor flash, debris and burrs. Our normal chemical mill removes .0003" - .0006" of material but can be increased to about .001". The advantages of Chemical Milling is that a thin layer of zinc oxide or carbonate deposited over a pure zinc die cast surface is removed and the potential for casting blisters can be eliminated. This also allows for high temperature applications without the casting blisters to appear under the intermetallic stresses that are formed from the copper plate.
Can You Explain Your Process Of Plating Zinc Die Casting?
With the exception of zinc plated parts, all zinc die-castings are processed as follows: preclean, mill, copper strike, and copper plate.
Preclean: A two step process to remove most synthetic, petroleum, vegetable, and animal based fluids used in die-casting and machining operations.
Mill: A controlled removal of the outer layer of die-cast. This process can remove flash, surface die-cast blisters, and modify dimensions if necessary. This step is essential to improve the adhesion of the subsequent copper plating.
Copper Strike: The copper strike is a specially formulated copper solution designed to provide excellent adhesion to the die-cast surface. The thickness of the strike is approximately 50 millionths of an inch.
Copper Plate: The copper plate seals the zinc to protect it from environmental exposure. Also, copper is used to modify dimensions. After the minimum thickness is achieved, we often add more copper to build dimensions. A thick, continuous copper plate is essential to protect the part from subsequent plating solutions which are corrosive to raw zinc.
Final Plate: After copper plating, the parts may safely be plated in nickel, tin, EN, etc.