Patent ID: 8446075

Claim:
A conductive film containing an elastomer and metallic filler particles filled in the elastomer, the metallic filler particles including anisotropic filler particles oriented in the film expansion direction having a flake-like or needle-like shape with a thickness of 1 μm or less, the conductive film satisfying the following conditions (A) and (B): (A) In a case where three straight lines extending in a film thickness direction are drawn on a film-thickness-direction cross-section photograph taken by using a scanning electron microscope with spacings at 3 μm each between the three straight lines in a film expansion direction; where, with respect to each of the straight lines, a count is made of the number of metallic filler particles that intersect the straight line and that each have a longest portion in the cross-section photograph with a length of 2 μm or more; and where, by dividing that number by the length of the straight line, a reference number per 1 μm of the straight line is calculated, an average value of the reference numbers of the three straight lines is 0.8 (1/μm) or more; or, the metallic filler particles include flake-like filler particles having a thickness of 1 μm or less and an aspect ratio of 26 or more, and the average value of the reference numbers is 0.4 (1/μm) or more; and (B) In a case where a measurement area formed by connecting 100 four-sided unit areas each with 2 μm per side is provided on the film-thickness-direction cross-section photograph taken by using the scanning electron microscope, and an area occupied by the elastomer in each of the unit areas is measured, a number of unit areas for which an area percentage of the elastomer is 60% or more is 20 unit areas or more.