Tin

Definition:
Tin is a soft, malleable, solderable deposit that is electrolytically applied to substrates. It is used for its resistance to corrosion, tarnishing and has the ability to preserve low contact resistance.

Spec(s):
Mil-T-10727

Classification(s):
Type I-Electro deposited tin

Mil-T-10727 was canceled in February of 1997, and the cancellation notice directs users to ASTM B545.

Spec(s):
ASTM B545-13

Classification(s):
KEY: Class – Minimum thickness, Typical applications
A – 2.5um or 0.0001″, Mild service conditions, providing corrosion and tarnish resistance, coatings that are not to be soldered
B – 5um or 0.0002″, Mild service conditions, coating that helps facilitate the soldering of electrical components, surface preparation for protective painting
C – 8um or 0.00032″, Moderate exposure conditions, usually indoors, retention of solderablitly of solderable articles during storage
D – 15um or 0.0006″, Severe service, exposure to dampness and mild corrosion from environment
E – 30um or 0.0012″, Very severe sercie conditions, including elevated temperatures, exposed to corrosive ligquies, atmosphere or gases
F – 1.5um or 0.00006″, Similar to class A but for shorter term contact applications and short shelf life requirements

Spec(s):
AMS 2408

3.1.1 Steel parts having a hardness of 40 HRC or higher and which have been ground after heat treatment shall be cleaned to remove surface contamination and stress relieved before preparation for plating. Unless otherwise specified, the stress relief shall be 275F +/- 25F for not less than 5 hours for parts with hardness of 55 HRC or greater and 375F +/- 25F for not less than 4 hours for other parts.

3.2.1 Except as stated in 3.2.1.2 or 3.2.2 tin shall be electrodeposited directly on the basis metal from a suitable tin plating bath.

3.2.1.2 Aluminum and aluminum alloys shall be zinc treated in accordance with ASTM B253 or other method acceptable to the cognizant engineering organization prior to plating.

3.2.2 Prior to electrodeposition of tin for solderability on aluminum or copper-zinc alloy parts, a copper plate shall be deposited to a thickness of 0.0002 to 0.0003 inch (5.1 to 7.6um)

3.4.1.1. Plate thickness may be specified by this specification number and a suffix number designating the minimum thickness in ten-thousandths of an inch (2.5um); thus, AMS 2408-1 designates a plate thickness of 0.0001 to 0.0003 inch, AMS 2408-6 designates a thickness of 0.0006 to 0.0008 inch, etc. A tolerance of 0.0002 inch will be allowed.

3.4.1.2. Where “tin flash” is specified, plate thickness shall be approximately 0.0001 inch.

Available Process(es):
Hand-line

Note:
JMD is offering a RoHS compliant Bright Tin plating.