Silicon-containing thermally conductive pastes

Process for producing crosslinkable silicone compositions, comprising:

• providing crosslinkable silicone composition (Y), wherein the crosslinkable silicone composition (Y) comprises 5-50% by volume of a crosslinkable silicone composition(S), 50-95% by volume of at least one thermally conductive filler (Z) having a thermal conductivity of at least 5 W/mK, wherein the crosslinkable heat-conducting silicone composition (Y) has a thermal conductivity of at least 0.6 W/mK, and wherein at least 20% by volume of metallic silicon particles present as thermally conductive fillers (Z) fulfil the following features:
• a) wherein the thermally conductive fillers (Z) have a median diameter x50 that is in the range of 30-150 μm;
• b) wherein the thermally conductive fillers (Z) are predominately rounded, and have a width/length ratio (aspect ratio w/l) that is at least 0.76;
• c) wherein the thermally conductive fillers (Z) have a distribution range SPAN ((x90−x10)/x50) that is at least 0.40;
• d) wherein the thermally conductive fillers (Z) contain at most 1.5% by weight of silicon particles that are smaller than 2 μm;
• and
• mixing the individual components.