IPC-4101

IPC-4101 lists out all of the IPC-accepted classifications for rigid and multilayer PCBs.  Calling out a slash sheet from this specification is the best way to designate a material to be used since your fab notes will always update along with the certification.

Common mistakes we see, especially for lead-free PCBs, are calling out laminate by either brand name, Tg, or Td. 

Below is a quick reference table for common 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