Construction to improve thermal performance and reduce die backside warpage
View Patent ↗A semiconductor package construction aimed at improving thermal performance. A heatspreader is provided having a metal alloy preform attached to it already. Then, a few dots of conductive epoxy are dispensed around the die. The heatspreader with the preformed metal alloy is pressed on the adhesive and then the part is cured. By coupling the die to the heatspreader with conductive epoxy, the die is constrained from warping. By removing the necessity of coating the die, the cost of fabrication is reduced. There is only a very marginal cost increase in the back end for dispensing the dots. For this, the process and equipment already exists in the backend. By reducing die backside warpage due, the die remains in good contact with the heatspreader, thus improving thermal performance.
1. A semiconductor package comprising: a substrate; a die on the substrate; a heatspreader; a metal layer on a portion of the heatspreader, said metal layer being in contact with a portion of the die, said heatspreader and said die having a space therebetween; and an adhesive disposed in the space between the die and the heatspreader disposed next to the metal layer on the heatspreader, thereby bonding the die to the heatspreader with the metal layer being disposed between the die and the heatspreader.
2. A semiconductor package as recited in claim 1 , wherein the metal layer on the heatspreader comprises a solder deposit.
3. A semiconductor package as recited in claim 1 , wherein the metal layer on the heatspreader comprises a metal alloy.
4. A semiconductor package as recited in claim 1 , wherein the adhesive comprises a conductive adhesive.
5. A semiconductor package as recited in claim 1 , wherein the adhesive comprises a conductive epoxy.
6. A semiconductor package as recited in claim 5 , wherein the conductive epoxy is disposed next to the metal layer on the heatspreader.
7. A semiconductor package as recited in claim 1 , wherein the adhesive is disposed next to, but not on, the metal layer on the heatspreader.
8. A method of constructing a semiconductor package to improve thermal performance, said method comprising:
providing a substrate having a die disposed thereon;
providing a heatspreader having a metal layer disposed on a portion thereof;
providing an adhesive between the die and the heatspreader next to the metal layer on the heatspreader;
bonding the die to the heatspreader such that the metal layer on the heatspreader is in adhesive contact with the die and the metal layer is disposed between the die and the heatspreader but is not adhered to the die.
9. A method as recited in claim 8 , wherein the step of bonding the die to the heatspreader comprises depositing an adhesive on at least one of the die and the heatspreader.
10. A method as recited in claim 9 , further comprising bringing the heatspreader and die toward each other such that the metal layer on the heatspreader contacts the die and the adhesive bonds the die and the heatspreader together with the metal layer being disposed between the die and the heatspreader.
11. A method as recited in claim 8 , wherein the step of bonding the die to the heatspreader comprises depositing a conductive adhesive on at least one of the die and the heatspreader.
12. A method as recited in claim 11 , further comprising bringing the heatspreader and die toward each other such that the metal layer on the heatspreader contacts the die and the conductive adhesive bonds the die and the heatspreader together with the metal layer being disposed between the die and the heatspreader.
13. A method as recited in claim 8 , wherein the step of bonding the die to the heatspreader comprises depositing a conductive epoxy on at least one of the die and the heatspreader.
14. A method as recited in claim 13 , further comprising bringing the heatspreader and die toward each other such that the metal layer on the heatspreader contacts the die and the conductive epoxy bonds the die and the heatspreader together with the metal layer being disposed between the die and the heatspreader.