BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell backsheet film,

摘要

A void-containing polyester film having a porosity of 10% or more as a whole of a film, wherein a line perpendicular to the surface direction is drawn from one surface of the film to the other surface on the cross section in the thickness direction of the polyester film, (C2 point), (C2-2 point) between the center point of the film thickness direction and the film surface (C2 point), and 3 points , The average area per one cavity existing on the dividing horizontal line passing through the point C1 is Sc (mu m ² ) and C2-1 Let Scs (탆 ² ) be the average area per one cavity on the dividing horizontal line passing through the point, and Scs' (탆 ² ) be the average area per one cavity on the dividing horizontal line passing through C2-2 , At least one of (Sc / Scs) and (Sc / Scs') 1.1 at least 35 or less, the polyester than 35 equivalents / ton in the amount of terminal carboxyl group of the polyester resin constituting the film solar battery backsheet film. A solar cell backsheet film capable of achieving excellent output improvement effect and adhesion, and a solar cell backsheet and a solar cell using the same.