IPC Lead-Free site: Current data and links

IPC: Association Connecting Electronics Industries

SMART Group: The SMART Group is the leading European technical trade association representing the electronics manufacturing industry.

Lead free soldering: A technical resource for design, process and quality engineers, managers and procurement staff having to deal with the 
introduction of lead-free materials and assembly processes.

Circuits Assembly: The Journal for Surface Mount and Electronics Assembly.

SMTA: MISSION OF THE SMTA
Over 20 Years Developing Solutions In Electronics Assembly.
The SMTA membership is a network of professionals who build skills, share practical experience and develop solutions in electronic assembly 
technologies and related business operations.

Arrow Electronics, Inc.: RoHS and Lead-Free Research Center, including data on component manufacturers.

Circuitnet Articles: A couple of editorials: 1 | 2

National Physical Laboratory: The Most Frequently Asked Questions on Lead-free.

RoHS Express: about the way you design products, buy products and do business in an increasingly green world.

Lead-Free Printed Circuit Board Finishes

With SnPb soldering processes HASL (SnPb) has been the predominant board finish followed by NiAu (ENIG) and OSP (Organic Solder Preservative). The following represent the most common board finishes to consider for a lead-free process. 

Board Finish

Comment

ENIG:

Electroless Ni / Immersion Au

Recommended in *JEITA Pb-free roadmap and predominant in Japan and EU. Price is generally a push compared with standard SnPb HASL process. Good corrosion resistance for on-board contact pads and suitable for wire bonding pads for COB designs.

HASL [SnAgCu or SnCu]

Recommended in *JEITA Pb-free roadmap and commonly used in Japan . Not commonly used in USA .

OSP –

Commonly used. Solderability more easily degraded by multiple reflows.

Immersion Ag

Good solderability and an increasingly significant board finish.

Immersion Sn

Commonly used in EU. Presence of carcinogenic thiourea in solutions has limited its use in USA .

*The Electronic Industries Association of Japan (EIAJ) and Japan Electronic Industry Development Association (JEIDA) merged effective November 1, 2000, to enter the 21st century as the Japan Electronics and Information Technology Industries Association (JEITA).