Method of fabricating a through-holed interposer
A through-holed interposer is provided, including a board body, a conductive gel formed in the board body, and a circuit redistribution structure disposed on the board body. The conductive gel has one end protruding from a surface of the board body, and an area of the protruded end of the conductive gel that is in contact with other structures (e.g., packaging substrates or circuit structures) is increased, thereby strengthening the bonding of the conductive gel and reliability of the interposer.
1. A method of fabricating a through-holed interposer, comprising:
providing a board body having opposing first and second surfaces and first and second protection layers formed on the first and second surfaces, respectively;
forming a plurality of through holes connecting the first surface and the second surface of the board body and extending to the first protection layer;
forming in each of the through holes a conductive gel having opposing first and second ends;
removing the first protection layer, to allow the first end of the conductive gel to protrude from the first surface of the board body;
forming a surface treatment layer on the first end of the conductive gel, wherein the surface treatment layer is in direct contact with the first end of the conductive gel;
forming on the first surface of the board body and the first end of the conductive gel a first circuit redistribution structure electrically connected to the first end of the conductive gel; and
removing the second protection layer to expose the second end of the conductive gel from the second surface of the board body.
2. The method of claim 1 , wherein the through holes further extend to the second protection layer, and the second end of the conductive gel protrudes from the second surface of the board body after the second protection layer is removed.
3. The method of claim 1 , further comprising, after removing the second protection layer, forming on the second surface of the board body and the second end of the conductive gel a second circuit redistribution structure electrically connected to the second end of the conductive gel.