To reduce the adhesion force between mold/EMC, it is
crucial to generate the surface with both low surface energy
and low polar components of surface energy. The surfaces with
reduced polar component are generally more hydrophobic. The
contact angle of water on different substrate materials with the
same surface roughness (Ra = 0.05 Am) were measured but only
limited differences, ranging from 72- to 83-, were observed.
The effect of the surface roughness on the contact angle of
water is shown in Fig. 5. The contact angle of AISI M2