Matte Tin -- Frequently Asked Questions
1. What is the difference between Matte Tin plating and Bright Tin plating? The primary differences are: 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. Grain size Matte Tin has a larger grain size than Bright Tin. Appearance Matte Tin has a normal whitish matte surface appearance whereas Bright Tin has a bright (shiny) surface finish. 2. I am transitioning to lead-free processing. Why should I choose Matte Tin? Matte Tin is readily available and has a successful track record of reliability. Matte Tin is compatible with all existing lead-alloy and Pb-free solders and pastes. Matte Tin tolerates the higher process temperatures required for lead-free processing. 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. 3. What is the composition of Matte Tin and Bright Tin? 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. 4. Are Matte Tin and Bright Tin compliant with the European Union RoHS Directive? The Matte Tin and Bright Tin platings applied by Samtec are compliant with the RoHS Directive (Directive 2002/95/EC). 5. Is Matte Tin compatible with leaded solder processes? Matte Tin is backward compatible with leaded solder processing. 6. Will Matte Tin prevent Tin Whiskers from forming? 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.
Samtec, Inc. 520 Park East Blvd. New Albany, IN 47151-1147 USA Samtec, Inc. 2005
WWW.SAMTEC.COM 1-800-SAMTEC-9 (US & Canada) lead-free@samtec.com Page: 1
Phone: 812-944-6733 Fax: 912-948-5047 Revision Date: 9/15/2005 All Rights Reserved
Matte Tin -- Frequently Asked Questions
7. Does Samtec use a barrier plating or underplating with Matte Tin? 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. 8. What is the thickness of the Matte Tin plating applied by Samtec? 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. 9. Is there a price penalty for Matte Tin? Presently, Samtec does not anticipate a price difference between Bright Tin and Matte Tin. 10. Will specifying Matte Tin impact my lead times? The lead times for the majority of Samtec products will not be affected by specifying Matte Tin plating. 11. Do I need to change my part numbers to specify Matte Tin? 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 callout (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. 12. Can I continue to order product with Bright Tin plating? It is the intent of Samtec to continue to support customers requesting Bright Tin plating. Bright Tin will remain Samtecs 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. 13. Can I continue to order product with Tin-lead plating? 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. 14. Will I receive a mixed shipment containing some Matte Tin plated parts and some Bright Tin plated parts? No. Product will be shipped bearing the plating specified by the part call-outs in the customer order.
Samtec, Inc. 520 Park East Blvd. New Albany, IN 47151-1147 USA Samtec, Inc. 2005
WWW.SAMTEC.COM 1-800-SAMTEC-9 (US & Canada) lead-free@samtec.com Page: 2
Phone: 812-944-6733 Fax: 912-948-5047 Revision Date: 9/15/2005 All Rights Reserved
