Fluxless die-to-heat spreader bonding using thermal interface material
AssigneeIntel Corporation
InventorsChuan Hu, Daoqiang Lu
Life of this patent
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Abstract
A thinned semiconductor die is coupled to an integrated heat spreader with thermal interface material to form a semiconductor package. The method for forming the package comprises forming a metallization layer on a backside of a thinned semiconductor die. A thermal interface portion, including a solder layer including a fluxlessly-capable solder such as AuSn, is formed on a topside of the integrated heat spreader. The metallization layer and the solder layer are then forced together under load and heat without flux to bond the semiconductor die to the integrated heat spreader.
Claims17
A semiconductor package comprising:
- a semiconductor die having a front side and an opposed backside;
- a backside metallization layer formed on the backside of the die;
- an integrated heat spreader;
- a thermal interface including a fluxlessly-capable solder portion deposited on a top surface of the integrated heat spreader and bonded to said metallization layer under load and heat;
- and
- said backside metallization layer including three layers including an adhesion/barrier layer, a wetting layer, and a protection layer.
A semiconductor package comprising:
- a semiconductor die having a front side and an opposed backside;
- a backside metallization layer formed on the backside of the die, said backside metallization layer including three layers including an adhesion/barrier layer, a wetting layer, and a protection layer;
- an integrated heat spreader;
- and
- a thermal interface including a fluxlessly-capable solder portion deposited on a top surface of the integrated heat spreader and bonded to said metallization layer under load and heat.
The semiconductor package of 13 wherein a thickness of Au layer and Sn layer is formed so that an overall Au-to-Sn ratio by weight is 80 to 20.
A semiconductor package comprising:
- a semiconductor die having a front side and an opposed backside;
- a backside metallization layer formed on the backside of the die;
- an integrated heat spreader;
- and
- a thermal interface including a fluxlessly-capable solder portion deposited on a top surface of the integrated heat spreader and bonded to said metallization layer under load and heat, wherein said backside metallization layer includes an adhesion/barrier layer, a wetting layer, and a protection layer, and said thermal interface layer includes a solder portion including gold (Au) and tin (Sn) together with a barrier layer formed of nickel (Ni) disposed between the solder portion and the integrated heat spreader.
Dependencies are inferred from the claim text.