Abstract: An anisotropic thermal interface device including plural aligned thermally anisotropic conductive composite layers. Each layer has a first thermal conductivity in a first direction and a second, larger thermal conductivity in a second direction. The aligned thermally anisotropic conductive composite layers extend substantially parallel to each other in the first direction and include 45-95 weight percent graphite flakes aligned in the second direction. The thermally anisotropic conductive composite layers have a binder including a branched siloxane. The thermally anisotropic conductive composite layers are adhered to adjacent thermally anisotropic conductive composite. The thermally anisotropic conductive composite layers have a second thermal conductivity of 25 to 45 W/mK. The anisotropic thermal interface device has an arithmetic average surface roughness of 5 to 20 ?m and a tensile strength of 50 to 130 KPa.