Hygroscopic Effects on Swelling and Viscoelasticity of Electronic Packaging Epoxy

One type of polymer EPN1180 is selected for the hygroscopic swelling tests and the sample is made in the thickness of 30mum . Coefficient of thermal expansion is tested by using DMA Q800 and coefficient of moisture expansion is tested by using DMA Q800 jointed with a humidity generator. Three conditions temperature, 50degC, 60degC, and 70degC, and different relative humidity with 20RH% steps are used for the tests and moisture induced expansion is characterized. The characterized equation can be used to expect the moisture-induced expansion at temperature between 0degC and 100degC, at relative humidity between 0RH% and 100RH% for this epoxy. This new method is convenient than that of the old method and easily is used to characterize other polymers. In addition, hygroscopic effect on the viscoelasticity is tested and characterized. The storage modulus is linear decreased with the increase of relative humidity at certain temperature