The thickness of the Matte Tin plating is part specific. The majority of products will have a minimum 150 micro-inch to 350 micro-inch plating thickness.

The specification range thickness of the matte tin is 300 micro inches to 800 micro inches. The target mean thickness is 450 micro inches. This thickness has been shown to retard tin whiskers, in conjunction with other process steps.

For high speed auto plating lines, MSA based electrolytes are most common. Numerous vendors such as Fidelity, Englehardt, LeaRonal, Isihara, Schlotter and other proprietary and home brews are readily available. For manual/rack/barrel plating lines, sulfuric acid based electrolytes are most common. Even more sources are readily available from numerous vendors such as above and lots of non-proprietary home brew chemistries. These are very inexpensive!

Temperature compatibility - Matte Tin is compatible with the elevated temperatures of lead-free, reflow processing (250-260C). Bright Tin has a tendency to discolor (turn dark) when exposed to the higher lead-free, reflow processing environment. Appearance - Matte Tin has a normal whitish "matte" surface appearance whereas Bright Tin has a bright (shiny) surface finish.

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.

A plating containing bright acid tin can discolor when exposed to the higher processing temperatures of lead-free, reflow soldering. Therefore it is recommended that the BAT be changed to change to Matte Tin. We are recommending that through hole parts with high temp insulators also be changed to a matte tin finish.

The application of the oil is so light that, in general, one teaspoon of oil can cover the area of a football field.

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

The thickness for gold coatings and platings are often expressed in millionths of an inch, microinches, or microns. The table below will help provide a basic translation between these units of measurements. To translate all this into real world plating thicknesses and their relationship to U.S. Gov. F.T.C. regulations, the following table expressed in microns is provided as a point of reference.

The Matte Tin and Bright Tin platings applied by Samtec are essentially 100% pure Tin. The Matte Tin applied by Samtec contains approximately 0.015% co-deposited organics as opposed to Bright Tin with approximately 0.15% co-deposited organics.

No high-Tin plating process can claim to be whisker-free. Copper/copper-alloy lead frames plated on a Nickel diffusion barrier are highly whisker resistant. All finish platings applied by Samtec are preceded by a Nickel diffusion barrier. Generally speaking, the thickness of the Nickel barrier underplating is 50 micro-inch minimum.

Aavid's plating recipe, 100% matte tin over a nickel barrier layer, follows the standard industry approach to whisker mitigation. We understand that whiskers typically occur when tin plating directly contacts a copper or copper alloy substrate, which then diffuse into each other, forming tin-copper intermetallic. This sets up compressive forces in the plane of the plating, causing 'extrusion' of tin whiskers.

The majority of our plating is lead free and/or RoHS compliant. CLX series or any contact that is pre-plated may not be compliant. Depending on the part number, plating call out and the processing temperatures you may need to choose a Matte Tin finish. Bright Acid Tin will discolor at the elevated processing temperatures of lead-free, reflow soldering and will need to be changed to Matte Tin (TM, LM, FM or SM plating designations).

The thickness of the tin coating for .25# coating is nominally 0.000015" on each surface. The thickness of the chrome coating is nominally 0.0000003" on each surface.

Once the 10+” of wool layers are stuffed into the cotton cover, the final thickness of the Cuddle Ewe Underquilt is approximately 3”. With use, the Cuddle Ewe Underquilt will compress to a thickness of about 1.5” to 2”. This is very normal and to be expected. Once the wool has compressed, there is nothing that can be done to re-fluff it, but it will still be comfortable. With proper care, you can maintain the Cuddle Ewe’s loftiness for a long time.

The type of tin (Sn) finish on leadframe products makes a difference in whisker growth. Several industry standard development organizations reject the use of shiny (or bright) tin. A matte tin finish is less susceptible to whisker growth. Freescale uses matte finish for tin plated leadframe products. Yes. The lead-free plated peripheral leadframe packages (such as SOIC, PLCC, QFP, etc.) are backward compatible with the conventional SnPb solders and board attach process.

Answer. To get the best optimum life, it is recommended that Sylgard HVIC be applied to a cured thickness of 0.5mm +/- 0.14mm and to achieve this, the uncured (wet) thickness should be approximately 0.7mm.

this time there is no standard test for Tin Whiskers. Mini-Circuits has done testing based on the conditions below: Thermal Cycling - 500 cycles It should be noted that we also make use of several process and material choices in order to mitigate the formation of intermetallics and whiskers, including:

The lead times for the majority of Samtec products will not be affected by specifying Matte Tin plating.

Until Samtec transitions to Matte Tin as "standard tin plating", one will need to specify Matte Tin plating by adding the Alpha character "M" immediately following the plating designator in the Samtec part call-out (note - does not apply to Tin-lead plating). Beginning March 1, 2006, Matte Tin will become the Samtec "standard Tin plating". There will be no need to specify Matte Tin by a part number change after this date.

It is the intent of Samtec to continue to support customers requesting Bright Tin plating. Bright Tin will remain Samtec's "standard tin plating" until March 1, 2006. After that date, if you prefer to specify Bright Tin plating, contact Samtec Customer Service at info@samtec.com for instructions.

Consistent with our past history, it is the intent of Samtec to continue to support customers requesting Tin-lead plating. The Tin-lead plating designators "-TL" (Tin-lead) and "-STL" (Selective Tin-lead) will remain valid plating designators for part call-outs. No. Product will be shipped bearing the plating specified by the part call-outs in the customer order.

The new plating will be 100% matte tin with a nickel barrier layer between the tin and the base material.

Are there any other technical or product specifications that are likely to be affected in the change to lead-free? If yes, please identify. This depends on the part number.

For smoothing applications, we usually recommend a chrome thickness of 0.002 inches (0.0508mm). Chrome thickness can be adjusted to suit your needs.

For applications where plating thickness is critical we periodically measure plated layers using a process called " x-ray fluorescence". This non-destructive method is very precise for measuring the actual metal deposition on an object after electroplating.

The Matte Tin and Bright Tin platings applied by Samtec are compliant with the RoHS Directive (Directive 2002/95/EC).

The larger grain size of Matte Tin (as compared to Bright Tin) creates less stress in the plating. Stress in pure Tin plating may be a root cause of tin whisker formation and growth.

For converting applications, we usually recommend a chrome thickness of 0.0003 inches (0.00762mm). Chrome thickness can be adjusted to suit your needs.

For sizing applications, we usually recommend a chrome thickness of 0.001 inches (0.0254mm). Chrome thickness can be adjusted to suit your needs.