Multilayer composite thermally-conductive sheet and preparation method therefor and use thereof

A multilayer composite thermally-conductive sheet, comprising a metal foil, two transition layers respectively provided on two opposite surfaces of the metal foil, and two low-temperature alloy layers respectively provided on surfaces of the transition layers facing away from the metal foil,

• wherein the metal foil is made from at least one selected from the group consisting of silver, copper, zinc, and platinum;
• the transition layers are made from one selected from the group consisting of indium and tin, and the transition layers have a thickness of 5-13 μm;
• and using GB/T 9286-1998 test standard, adhesion of the transition layers to the surfaces of the metal foil is of grade 0;
• and
• a melting point of the low-temperature alloy layers is 30-300° C.