TG140, TG150 or TG170

[48X24X48X]

Hi guys,

I read some IPC standards about lead free assembly on the requirement needed for the PCB material.
It seems for lead free assembly it needs to be TG150 at least together with some other criterias (Td, T-260 test, T-288 test and Z-axis CTE). What you guys normally use? Do you guys observe any lamination coming off issues while reflowing at higher temperature with normal TG140 FR4?

[Alphatronique]

HI

most of big PCB shop use lead free laminate since long time
not that ti keep dual inventory and most customer need lead free
for be able to export export it product

for same reason i do all my assembly in lead free ..

so probably only small local PCB shop still use old laminate ?

Best regard

[48X24X48X]

The laminate material can be lead free but still fail to go through lead free reflow process because of higher temperature requirement. That is why they have different material rating that falls under different IPC standard subclass.

[Alphatronique]

HI

i not read back all my IPC book since some time so it not very fresh to my memory

but i will find funny that a pcb shop will use lead-free pcb that not handle lead free process (reflow)
any pcb will go higher that it TG point during reflow and that make stress on via barrel (z)
but normally it only < 3 reflow run so it not a every day thermal stress or operating condition

normally standard commonly used laminate was now isola 410

if you have relfow delamination issue i will check first reflow most small batch oven (IR)
have bad /uneven temperature ... or check pcb quality old prepeg may cause that issue to

during year that i have run a pcb shop only time i see delamination issue was whit very old prepeg
now i have close my shop since asian pcb shop like internationalcircuits.com do it for less that my material cost ....
whit really good quality