Lead Free Resource Center

Welcome to Alpha's Lead Free Resource Center.  We've reserved this area of the site to consolidate materials and information pertinent to lead-free printed circuit boards.  Topics range from laminate and final finish considerations to fabrication and assembly guidelines.  Should you require information on a topic that you don't find here, please send a note to Bob Hammond (bobh@alphacircuit.com) and we'll gladly research it for you.

Pre-Bake Suggestions for Common Lead-Free Final Finishes
Final Finish Temperature  Time               Comments
Tin                   125°C 4 hours Higher Temp may reduce solderability
Silver 150°C 4 hours Silver may tarnish, but solderability should not be affected
ENIG 150°C 4 hours No issues with extended bak on ENIG finish
OSP 105°C 4 hours Extended bake cycles may negatively impact multiple heat cycle assembly processes



Commonly Called Out Lead-Free Capable Materials

  4101/99, /124 4101/101, /121 4101/126, /129
Resin System      
Primary Epoxy Difunctional Epoxy Epoxy
Secondary 1 Multifunctional Epoxy Multifunctional Epoxy Multifunctional Epoxy
Secondary 2 Modified Epoxy or Non-epoxy (max 5%) Modified Epoxy or Non-epoxy (max 5%) Modified Epoxy or Non-epoxy (max 5%)
Fillers /99:  Inorganic
/124: None
/101: Inorganic
/121: None
/126: Inorganic
/129: None
Tg 150 C min. 110 C min. 170 C min.
Td 325 C min. 310 C min. 340 C min.
T260 (min) 30 min 30 min 30 min
T288 (min) 5 min 5 min 15 min
T300 (min) ABBUS ABBUS 2 min

Click here to see full version of Isola Lead Free Assembly Guidelines


Articles
Latest on Lead-Free Capable Materials

PCB Magazine February 2012

Advancements in lead-free materials are not necessarily restricted to the materials themselves; they often develop in our knowledge base of the characteristics and performance criteria of the already available library of materials in the marketplace. This is truly the low-hanging fruit.

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