Hi,
The laminates below have a good balancing of the important qualities, Td, CTE
[actually thermal expansion, TE], Z axis stability, Tg(TMA--other methods
inflate the value), etc.

Polyclad PCL-370HR:  Tg=>170(DSC)/170(TMA), Td=345, T-260=>??/T-288=>??,
TE=2.7%
Nelco 4000-11:         Tg=180(DSC)/~165(TMA), Td=350, T-260=30/T-288=>??,
TE=3.2%
Isola IS410:                 Tg=180(DSC)/~165(TMA), Td=350, T-260=>60/T-288=>
10, TE=3.5%

How do you get an overall picture of this balancing act? I have suggested a
Soldering Temperature Impact Index (STII) defined as follows:

STII = Tg(TMA)/2 + Td(5%)/2 - [TE(50 to 260)%]x10, with a minimum of STII =
215

Thus, the 3 materials have

Polyclad PCL-370HR:  STII=230
Nelco 4000-11:         STII=225
Isola IS410:                 STII=222



Werner

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