In part 1 of this blog post I commented upon the affect the assembly process has upon a printed circuit board. The assembly temperatures applied do in fact burn away the epoxy of the FR-4 composite material. The higher the temperature the faster the rate of burn. I touched upon the relation ship between the glass transition temperature (Tg), decomposition temperature (Td) and the Maximum continuous Operating Temperature (MOT). There is another gauge that can be used to help a designer or contract assembler understand this point and that is the Time to delamination test. These are referred to as either the T260 or T288 tests.
What is the T260/T288 Time to Delamination? This is a test defined by (more…)