Hi Jaya

It is difficult to tell if you have a background problem or just little/no signal from your primary antibody, since if what you are showing is auto-contrasted then no signal will always appear as high background.

When testing a new antibody I always use ECL detection since this is more sensitive. If the antibody gives good signal then I am happy to use fluorescent detection, but if the signal is weak then I would optimise further or just stick to ECL for that antibody. Fluorescent detection unavoidably has higher background, so for very weak antibodies or low abundance proteins you may not be able to detect anything meaningful.

If what you do have is a high background problem then I have a couple of suggestions:

Firstly, you can use 0.02 % SDS and 0.1 % Tween20 in your diluted secondary antibody. This is essential if you are using 680LT antibodies from LiCor with PVDF, but I use it for all fluorescent secondaries and find that it helps (I am also using Immobilon-FL by the way). 

Secondly, do not let the membrane dry before/during imaging, as this increases background.

Thanks Alex.