Lead Free Flex PCB Resource Center

Welcome to Saturn Flex Systems' Pb-Free Resource Center.  

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 contact us and we'll gladly research it for you.

Pre-Bake Suggestions for Pb-Free Final Finishes

  Final Finish Temp   
Shelf Life   Comments
  Tin                  125°C   4 hrs 
3 mths  
  Higher Temp may reduce solderability
  Silver  150°C   4 hrs  6 mths   Silver may tarnish, but solderability should not be affected
  ENIG  150°C   4 hrs  12 mths   No issues with extended bake on ENIG finish
  OSP  105°C   4 hrs  3 mths   Extended bakes negatively impact multiple heat cycle assembly

Commonly Called-Out Pb-Free Capable Materials
Click here for Isola Lead Free Assembly Guidelines

  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

Latest on Lead-Free Capable Materials
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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